Saturday

November 28, 2015
Number of results: 23,095

**physics - SHM**

Two sinusoidal waves with identical wavelengths and amplitudes travel in opposite directions along a string with a speed of 11 cm/s. If the time interval between instants when the string is flat is 0.33 s, what is the wavelength of the waves? wavelength = (wave speed) / (...
*April 14, 2007 by COFFEE*

**physics**

Halley's comet moves about the sun in an elliptical orbit with its closest approach to the SUn being .59AU and its greatest distance being 35AU (1AU=Earth-sun distance) if the comet's speed at closest approach is 54km/s what is its speed when it is farthest from the Sun? you ...
*January 29, 2007 by cyndi*

**Physics**

A small boat is crossing a river which flows at 10km.h. The driver of the boat keeps it heading directly (at 90) away from the bank at a speed of 24 km/h relative to the water. The river is 0.5 km wide. I calculated the speed of the boat relative to land - 26km/h I calculated ...
*February 26, 2008 by Anonymous*

**PHYSICS WORK PROBLEM due tonight!! please help!**

A ball of mass 522 g starts at rest and slides down a frictionless track, as shown below. It leaves the track horizontally, striking the ground a distance x = 0.93 m from the end of the track after falling a vertical distance h2 = 1.18 m from the end of the track. (a) At what ...
*April 15, 2010 by brittany*

**AP Physic**

Hi there I am having so much problems trying to solve this physic problem and I really need help. Please give me a big hint on how to find the amplitude of this problem because i tried using everything i know and i cannot figure it out. This homework problem deals with wave ...
*January 17, 2010 by shylo*

**physics**

The motor of a fan turns a small wheel of radius rm = 1.60 cm.This wheel turns a belt, which is attached to a wheel of radius rf = 2.90 cmthat is mounted to the axle of the fan blades. Measured from the center of this axle, the tip of the fan blades are at a distance rb = 11.0...
*October 21, 2011 by mymi*

**Physics**

Speed of Asteroids With the same Radius? Two spherical asteroids have the same radius R . Asteroid 1 has mass M and asteroid 2 has mass 2M. The two asteroids are released from rest with distance 10R between their centers. What is the speed of each asteroid just before they ...
*April 12, 2011 by Dan*

**physics **

The figure shows a golf ball passing through a windmill at a miniature golf course. The windmill has 8 blades and rotates at an angular speed of 2.02 rad/s. The opening between successive blades is equal to the width of a blade. A golf ball of diameter 3.27 x 10-2 m is just ...
*March 8, 2012 by Andrew*

**Physics**

For a given initial projectile speed, you observe that the projectile has a certain range R at a launch angle A = 30 degrees. For what other launch angle will the projectile have the same range (assuming the same initial projectile speed)? Without the use of mathematical ...
*February 17, 2014 by Tim*

**math**

The runway of an airfield faces west. An airplane, flying in the direction of north-east at a height of 2km and at a speed of 400km/h, on a path which passes over a point 3km west of the runway end, is spotted sqrt(29)km horizontally(south-western quadrant) from the runway end...
*November 20, 2011 by Jainee*

**Physics**

A golfer hits a shot to a green that is elevated 3.10 m above the point where the ball is struck. The ball leaves the club at a speed of 19.4 m/s at an angle of 33.0˚ above the horizontal. It rises to its maximum height and then falls down to the green. Ignoring air ...
*October 17, 2014 by Tami*

**physics**

A person walking with a speed of 1.44 m/sec releases a ball from a height of h = 1.28 m above the ground. Use the point on the ground, directly below where the ball is initially released at the origin of your coordinate system. (a) What is the ball's position at 0.25 seconds ...
*September 11, 2011 by Katie*

**Math Hurry!**

Gabriela traveled by motorcycle at an average speed of 17 miles per hour. Then, she traveled by car at an average speed of 12 miles per hour. In total, she traveled 56 miles for 4 hours. How many miles did Gabriela travel by car? (Round to the nearest mile.)
*October 30, 2012 by Sonja*

**math**

A town N is 340 km due west of town G and town K is west of town N. A helicopter Zebra left G for K at 9.00 a.m. Another helicopter Buffalo left N for K at 11.00 a.m. Helicopter Buffalo traveled at an average speed of 20 km/h faster than Zebra. If both helicopters reached K at...
*March 1, 2015 by kudu*

**math**

A town N is 340 km due west of town G and town K is west of town N. A helicopter Zebra left G for K at 9.00 a.m. Another helicopter Buffalo left N for K at 11.00 a.m. Helicopter Buffalo traveled at an average speed of 20 km/h faster than Zebra. If both helicopters reached K at...
*March 6, 2015 by kudu*

**Physics**

two air carts of mass m1=0.87kg and m2=0.48kg are placed on a frictionless track.cart 1 is at rest initally, and a spring bumper with a force constant of 690N/m. cart 2 has a flat metal surface for a bumper, and move toward the bumper of the stationary cart with an intial ...
*November 23, 2015 by Has*

**College Physics**

Modern airplane design calls for a lift, due to the net force of the moving air on the wing, of about 2000 N per square meter of wing area. Assume the air flows past the wing of an aircraft with streamline flow. If the speed of flow past the lower wing surface is 120m/s, what ...
*November 13, 2007 by Jen*

**Physics**

A bicycle and rider of total weight 815 N travel at a speed of 40.0 km/h. The rider hits the breaks and the bicycle slides to a full stop in a distance of 8.5 m. Ignore air resistance and use g=9.8 m/s2. What is the coefficient of kinetic friction between the tires (rubber) ...
*October 22, 2009 by Nikita*

**physics**

A uranium nucleus 238 U may stay in one piece for billions of years, but sooner or later it decays into an α particle of mass 6.64×10 −27 kg and 234 Th nucleus of mass 3.88 × 10 −25 kg, and the decay process itself is extremely fast (it takes about 10 −...
*January 22, 2011 by Anonymous*

**Physics**

Please help I've attempted this problem various ways and I can't seem to get the correct answer. A 69.0 kg person throws a 0.0410 kg snowball forward with a ground speed of 35.0 m/s. A second person, with a mass of 60.0 kg, catches the snowball. Both people are on skates. The ...
*June 3, 2011 by Kristen*

**Physics**

Please help I've attempted this problem various ways and I can't seem to get the correct answer. A 69.0 kg person throws a 0.0410 kg snowball forward with a ground speed of 35.0 m/s. A second person, with a mass of 60.0 kg, catches the snowball. Both people are on skates. The ...
*June 3, 2011 by Kristen*

**physics**

What will a spring scale read for the weight of a 50 kg woman in an elevator that moves as follows? (a) upward with constant speed of 3.0 m/s Enter a number.1 N (b) downward with constant speed of 3.0 m/s Enter a number.2 N (c) upward with acceleration of 0.35g Enter a number....
*December 18, 2009 by kim*

**math**

Benjamin and Bob are marathon runners on a run from landmarks P to Q. Benjamin runs half the way and walks the other half. Bob runs half the time, and walks the other half. The two run at the same speed and walk at the same speed. Who finishes first?
*September 22, 2014 by j*

**Physics**

Eris, the largest dwarf planet known in the Solar System, has a radius R = 1200 km and an acceleration due to gravity on its surface of magnitude g = 0.77 m/s2. (a) Use these numbers to calculate the escape speed from the surface of Eris. (b) If an object is fired directly ...
*June 29, 2012 by James*

**physics - speed of electron in magnetic field **

A beam of electron is accelerated by a potential difference of 2.5okV. The electrons are then allowed to pass into a magnetic field of strength 10.0mT. As the electrons enter the field, the direction of the velocity is at right angles to the direction of the magnetic field. ...
*December 5, 2010 by Farah*

**Physics**

A. A baseball is seen to pass upward by a window 28.1 m above the street with a vertical speed of 13.7 m/s. If the ball was thrown from the street, what was its initial speed? B. What altitude does it reach? C. How long before the ball passed the window was it thrown? D. How ...
*August 21, 2012 by Ashley*

**physics**

• If you use a cart with half the mass, you reach _______final speed. • If you use half the force, you reach ______ final speed. • If you push twice as long, you cover _______ distance during pushing. • If you use a cart with half the mass, you cover_______ distance during ...
*February 17, 2014 by Ted*

**physics**

A small ball rolls horizontally off the edge of a tabletop that is 1.2 m high. It strikes the floor at a point 1.52m horizontally away from the edge of the table. a) How long is the ball in the air? b) What is the speed at the instant it leaves the table? I don't understand ...
*October 24, 2006 by jenny*

**Physics**

The Falling Paint Can: A painter is standing on scaffolding that is raised at a constant speed vi. As he travels upward he accidentally nudges a paint can off the scaffolding and it falls 15m to the ground. You are watching and measure with your stopwatch that it takes 3.25s ...
*November 20, 2012 by Zalak*

**Physics**

Car A travels with speed v around curve number one, which has a radius r. Car B travels with speed 2v around curve number two, which has a radius 2r. What is the ratio of the two accelerations A/B? A) 2 B) 4 C) 1/2 D) 1/4 E) 1
*July 8, 2014 by Anonymous*

**Physics**

Car A travels with speed v around curve number one, which has a radius r. Car B travels with speed 2v around curve number two, which has a radius 2r. What is the ratio of the two accelerations A/B? A) 2 B) 4 C) 1/2 D) 1/4 E) 1
*July 8, 2014 by Anonymous*

**Physical scince please help **

What happens to the particles inside the balloon?do the... A) increase in speed B) decrease in speed C) the particles increase in size D) the particles decrease in size E) increase in number F) decrease in number G) something else happens like_____________
*September 26, 2012 by Darcy *

**physics**

A stunt driver wants to make his car jump over eight cars parked side by side below a horizontal ramp a)With what minimum speed must he drive off the horizontal ramp? The vertical height of the ramp is 1.5m above the cars, and the horizontal distance he must clear is 20m . ...
*November 24, 2012 by juanita*

**Physics/Math**

A certain string can withstand a maximum tension of 43 N without breaking. A child ties a 0.37 kg stone to one end and, holding the other end, whirls the stone in a vertical circle of radius 0.91 m, slowly increasing the speed until the string breaks. Where is the stone on its...
*February 12, 2007 by COFFEE*

**Physics Correction**

You drop a ball from a window on an upper floor of a building and it is caught by a friend on the ground when the ball is moving with speed vf. You now repeat the drop, but you have a friend on the street below throw another ball upward at speed vf exactly at the same time ...
*February 7, 2012 by Haroula*

**Physics**

At what temperature is the rms speed of helium molecules half its value at STP (0 C, 1.0 atm})?(answer in K) I think i need to use V_rms=sqrt3kT/m k=1.38e^-23J/K helium has 4g so i think helium molecule is 4/6.02e23 but i don't know how to proceed further then i have to answer...
*November 22, 2009 by ana*

**physics**

A car has a flywheel ( a diks of R=0.2m and uniformly distributed mass M=100kg) that can convert 25% of the rotational kinetic energy into translational kinetic energy. The mass of the car is 1000kg ( including flywheel). Suppose the car is at rest, and the flywheel has a ...
*December 30, 2013 by Al*

**physics**

A fisherman sets out upstream from Metaline Falls on the Pend Oreille River in northwestern Washington State. His small boat, powered by an outboard motor, travels at a constant speed v in still water. The water flows at a lower constant speed vw. He has traveled upstream for ...
*February 16, 2011 by Anonymous*

**physics**

A fisherman sets out upstream from Metaline Falls on the Pend Oreille River in northwestern Washington State. His small boat, powered by an outboard motor, travels at a constant speed v in still water. The water flows at a lower constant speed vw. He has traveled upstream for ...
*February 18, 2011 by Anonymous*

**Physics**

A pendulum consists of a 2.6 kg stone swinging on a 4.5 m string of negligible mass. The stone has a speed of 7.9 m/s when it passes its lowest point. (a) What is the speed when the string is at 53 ¢ª to the vertical? (b) What is the greatest angle with the vertical that the ...
*October 25, 2012 by Cody*

**Physics**

A pendulum consists of a 2.1 kg stone swinging on a 3.6 m string of negligible mass. The stone has a speed of 7.9 m/s when it passes its lowest point. (a) What is the speed when the string is at 60° to the vertical? (b) What is the greatest angle with the vertical that the ...
*November 7, 2014 by Jake*

**physics**

hi i have a physics question i dont understand here is the question A sample of blood is placed in a centrifuge of radius 15 cm. the mass of the corpuscle is 3.0*10^-16 kg, and the magnitude of the force required to make it settle out of the plasma is 4.0X10^-11 N. At how many...
*January 2, 2007 by becky*

**Physics**

A boat moves through the water of a river at 5 m/s relative to the water, regardless of the boat's direction. If the water in the river is flowing at 1.3 m/s, how long does it take the boat to make a round trip consisting of a 215 m displacement downstream followed by a 215 m ...
*June 1, 2008 by Elisa*

**Physics**

A boat moves through the water of a river at 5 m/s relative to the water, regardless of the boat's direction. If the water in the river is flowing at 1.3 m/s, how long does it take the boat to make a round trip consisting of a 215 m displacement downstream followed by a 215 m ...
*June 1, 2008 by Elisa*

**physics**

A trapeze artist sailing through the air rotates with a rotational speed of 0.9·rev/s. If she contracts to reduce her rotational inertia to one sixth of what it was, what will her new rotational speed be? _____ rev/s? Can she completely stop her rotation while still airborne? ...
*February 6, 2013 by wally*

**Physics- so confused!!**

A bullet with a mass of 5.40 g is fired horizontally at two blocks resting on a smooth and frictionless table top as shown in the Figure. The bullet passes through the first 1.20 kg block, and embeds itself in a second 1.20 kg block. Speeds v1 = 3.90 m/s and v2 = 1.70 m/s, are...
*March 23, 2013 by Julia*

**Physics**

A liquid (density = 1.65 g/cm^3) flows through two horizontal sections of tubing. In the first section the cross-sectional area is 10.0 cm^2, the flow speed is 275 cm/s, and the pressure is 1.20 x 10^5 Pa. This tubing then rises 50 cm to the second horizontal section which has...
*November 11, 2010 by Daniel*

**Calculus**

Suppose that two boats leave a dock at different times. One heads due north, the other due east. Find the rate at which the distance between the boats is changing when the first boat is 56 miles from the dock traveling at a speed of 35 miles per hour and the second boat is 20 ...
*October 7, 2014 by Hailey*

**Physics**

A revolutionary cannon, with a mass of 2000kg, fires a 20kg ball horizontally. The cannonball has a speed of 140m/s after it has left the barrel. The cannon carriage is on a flat platform and is free to roll horizontally. What is the speed of the cannon immediately after it ...
*September 18, 2006 by puff puff*

**Physics**

2-A 10.0 Kg block is released from point A in the figure below. The block travels along a smooth frictionless track except for the rough 1 m long portion between points B and C. It makes a collision with stationary 10 kg ball after passing point C. The ball moves forward with ...
*June 2, 2013 by Maryam*

**sciece**

compare and contrast deer population growth to human population growth in terms of a. predation and competition and b. speed of population response. I don't understand predation in terms of human population growth (can someone explain please)? I do not understand speed of ...
*September 9, 2009 by cara*

**Physics**

1)As a sound source moves away from a stationary observer, the number of waves will. A)increase B)decrease C)remain the same D)need to know the speed of the source (answer:decrease.) As the detector recedes from the source, the relative velocity is smaller, resulting in a ...
*April 7, 2008 by Jon*

**Physics**

A ballistic pendulum was a device used in the past century to measure the speed of bullets. The pendulum consists of a large block of wood suspended from long wires. Initially, the pendulum is at rest. The bullet strikes the block horizontally and remains stuck in it. The ...
*October 26, 2012 by Jeff*

**physics**

A car initially traveling eastward turns north by traveling in a circular path at uniform speed as in the figure. The length of the arc ABC is 259 m, and the car completes the turn in 38.0 s. a)Determine the car's speed.m/s b)What is the magnitude and direction of the ...
*October 18, 2012 by Karrine*

**physics**

Assuming 95.0% efficiency for the conversion of electrical power by the motor, what current must the 12.0 V batteries of a 740 kg electric car be able to supply: (a) To accelerate from rest to 25.0 m/s in 1.00 min? (b) To climb a 200 m high hill in 2.00 min at a constant 25.0 ...
*September 15, 2013 by Justin*

**physics**

Assuming 95.0% efficiency for the conversion of electrical power by the motor, what current must the 12.0 V batteries of a 740 kg electric car be able to supply: (a) To accelerate from rest to 25.0 m/s in 1.00 min? (b) To climb a 200 m high hill in 2.00 min at a constant 25.0 ...
*September 15, 2013 by Justin*

**Physics**

A stunt driver wants to make his car jump over 8 cars parked side by side below a horizontal ramp. A)With what minimum speed must he drive off the horizontal ramp? The vertical height of the ramp is 1.5 m above the cars and the horizontal distance he must clear is 22..(I got ...
*December 6, 2013 by Somoan*

**sciecne**

A space station has the form of a hoop of radius R = 15 m, with mass M = 6000 kg. Initially its center of mass is not moving, but it is spinning slowly with angular speed ù0 = 0.0018 radians/s.Then a small package of mass m = 5 kg is thrown by a spring-loaded gun toward a ...
*July 30, 2014 by sara*

**science**

A science student drops a rok down a mine shaft. It takes 3 sec. for the rock to hit the bottom of the shaft , at what speed of the rock just before impact? 32 feet per second per second is the acceleration rate of earth. At the end of second 1 the speed is 32 feet per second...
*October 24, 2006 by pat*

**Physics**

A hot air balloon is ascending straight up at a constnat speed of 7.0 m/s. When th balloon is 12.0 m above the ground, a gun fires a pellet straight up from ground elvel with an initial speed of 30,0 m/s. Along the paths of the balloon and the pellet, there are two places ...
*January 2, 2009 by Anonymous*

**physics please help!!**

A distant galaxy is simultaneously rotating and receding from the earth. As the drawing shows, the galactic center is receding from the earth at a relative speed of uG = 1.90 106 m/s. Relative to the center, the tangential speed is vT = 3.00 105 m/s for locations A and B, ...
*March 27, 2012 by linds*

**Physics please help cant figure this out**

starting with an initial speed of 5.00 m/s at a height of 0.265 m, a 1.75 kg ball swings downward and strikes a 4.45 kg ball that is at rest, as the drawing shows. (a) Using the principle of conservation of mechanical energy, find the speed of the 1.75 kg ball just before ...
*November 5, 2010 by joseph *

**physics**

In the Daytona 500 auto race, a Ford Thunderbird and a Mercedes Benz are moving side by side down a straight-away at 66.5 m/s. The driver of the Thunderbird realizes that she must make a pit stop, and she smoothly slows to a stop over a distance of 250 m. She spends 5.00 s in ...
*January 21, 2012 by sarah*

**Physics**

In the Daytona 500 auto race, a Ford Thunderbird and a Mercedes Benz are moving side by side down a straight-away at 67.5 m/s. The driver of the Thunderbird realizes he must make a pit stop, and he smoothly slows to a stop over a distance of 250 m. He spends 5.00 s in the pit ...
*January 23, 2015 by Jerry*

**Physics**

A ball of mass 0.640 kg moving east (+x direction) with a speed of 3.10 m/s collides head-on with a 0.780 kg ball at rest. If the collision is perfectly elastic, what will be the speed and direction of each ball after the collision? 1. ball originally at rest 2. ball ...
*November 24, 2009 by Fred*

**physics**

In the absence of air resistance two balls are thrown upward from the same launch point. Ball A rises to a maximum height above the launch point that is four times greater than that of ball B. The launch speed of ball A is _______ times greater than that of ball B. a)2 b)4 c)8...
*September 8, 2010 by Brantley*

**physics**

A bowling ball encounters a 0.76m vertical rise on the way back to the ball rack. Ignore frictional losses and assume that the mass of the ball is distributed uniformly. If the translational speed of the ball is 3.80m/s at the bottom of the rise, find the translational speed ...
*March 28, 2007 by Cavin*

**Calculus**

this homework is due in one hour and i have no idea how to answer these questions. 1. A car is traveling at 50 mi/h when the brakes are fully applied, producing a constant deceleration of 20 ft/s^2. What is the distance covered before the car comes to a stop? 2. A stone is ...
*November 16, 2011 by Sam*

**Physics**

what are the forces acting on a string that is wounded around a uniform disk of Radius R and mass R? i know tension is in the string...what else? and I of the disk is 1/2 MR2... so how would you show that the tension in the string is one third the weight of the disk? and......
*December 15, 2008 by Stacu*

**Physics**

A 0.26 kg rock is thrown vertically upward from the top of a cliff that is 27 m high. When it hits the ground at the base of the cliff the rock has a speed of 24 m/s. (a) Assuming that air resistance can be ignored, find the initial speed of the rock. (b) Find the greatest ...
*March 29, 2010 by Carden*

**Machanics**

An electron moving at a speed of 5 multiply by 10 raise to power six m/s was shot through a sheet of paper which is 2.1 multiply by 4cm thick.the electron emerges from the paper with a speed of 2 multiply by 10 raise to power six m/s,find the time taken by the electron to pass...
*January 13, 2013 by Anonymous*

**Physics**

In a World Cup soccer match, Juan is running due north toward the goal with a speed of 7.70 relative to the ground. A teammate passes the ball to him. The ball has a speed of 13.3 and is moving in a direction of 30.5 east of north, relative to the ground. a) what is the ...
*September 25, 2012 by Annie*

**physics--please help**

You are traveling in a car toward a hill at a speed of 40.8 mph. The car's horn emits sound waves of frequency 243 Hz, which move with a speed of 340 m/s.The frequency with which the waves strike the hill is 254.7Hz and the frequency of the reflected sound waves you hear 271.2...
*April 1, 2012 by sara*

**physics--please help**

You are traveling in a car toward a hill at a speed of 40.8 mph. The car's horn emits sound waves of frequency 243 Hz, which move with a speed of 340 m/s.The frequency with which the waves strike the hill is 254.7Hz and the frequency of the reflected sound waves you hear 271.2...
*April 1, 2012 by sara*

**math**

The wave heights h in the open sea depend on the speed v of the wind and the length of time t that the wind has been blowing at that speed. Values of the function h = f(v, t) are recorded in feet in the following table. the values that you need on the table are.. 20hr/30 knots...
*September 23, 2014 by sara*

**Math**

Flying into the wind, a plane takes 8 h to travel 5432 km from Paris to Montreal. The same plane flying with the wind from Montreal to Paris takes only 7 h. Find the speed of the plane and the speed of the wind. Can you plz answer this sir I really would appriciete it. Plz can...
*January 22, 2009 by gagan*

**Physics**

Water flowing through a garden hose of diameter 2.77 cm fills a 25.0-L bucket in 1.40 min. (a) What is the speed of the water leaving the end of the hose? Answer in m/s (b) A nozzle is now attached to the end of the hose. If the nozzle diameter is one-third the diameter of the...
*March 30, 2014 by Renee*

**Physics**

I did a lab in which we were to find the 1st resonance and 2nd resonance and from them we found wavelength which in turn helped us find speed of sound. We used tuning forks and the frequancy was given. We besically moved a plastic tube which was in water up along with he ...
*March 8, 2009 by Lena*

**Physics**

A proton is moving toward a charge of + 2.8 nC. On its way in to the charge it passes Point B at 4.5 cm from the charge and then passes Point A at 1.2 cm as it gets closer to the charge. a. What is the potential difference between points B and A? b. What is the change in ...
*February 10, 2011 by So Confused*

**Physics**

Find the speed at which Superman (mass=88.0 kg) must fly into a train (mass = 17998 kg) traveling at 60.0 km/hr to stop it. Running into the train at that speed would severely damage both train and passengers. Calculate the minimum time Superman must take to stop the train, if...
*March 29, 2011 by Lily*

**Physics**

Find the speed at which Superman (mass=88.0 kg) must fly into a train (mass = 17998 kg) traveling at 60.0 km/hr to stop it. Running into the train at that speed would severely damage both train and passengers. Calculate the minimum time Superman must take to stop the train, if...
*March 27, 2011 by Daniel*

**physics**

football is kicked off with an initial speed of 66 ft/s at a projection angle of 45 degrees. A receiver on the goal line 63 yd away in the direction of the kick starts running to meet the ball at that instant. What must be his minimum speed (in feet/second) if he is to catch ...
*September 30, 2013 by lucas*

**modern physics**

A pi meson of mass m moves with a speed u in the positive y direction in frame S with parameters BETA = u/c and GAMMA = 1/[sqrt(1 - BETA^2)]. The pion decays into two gamma rays. An observer S' moves in the positive x direction with speed v = BETA'c and detects the two photons...
*October 13, 2006 by Anonymous*

**Impulse and Momentum**

In the game of billiards, all the balls have approximately the same mass, about 0.20 kg. The cue ball moving west with a speed of 4.5m/s strikes another ball at rest. After the collision the cue ball moves at an angle of 55degree north of west and the other ball at an angle of...
*March 1, 2015 by Jennifer*

**physics**

An elevator without a ceiling is ascending with a constant speed of 9.7 m/s. A boy on the elevator shoots a ball directly upward, from a height of 2.0 m above the elevator floor, just as the elevator floor is 25 m above the ground. The initial speed of the ball with respect to...
*September 21, 2010 by kay*

**math**

A motorcycle leaves Colorado Springs traveling north at an average speed of 47 miles per hour. One hour later, a car leaves Colorado Springs traveling south at an average speed of 54 miles per hour. How long after the motor cycle leaves will it take until they are 552 miles ...
*May 31, 2011 by elaine*

**physics**

A 0.145 kg block is released from rest from the top of a 51.7◦ frictionless incline. When it has fallen a vertical distance of 1.3 m, a 0.00794 kg bullet is fired into the block along a path parallel to the slope of the incline, and momentarily brings the block to rest, ...
*April 9, 2010 by Jen*

**Physics**

A 2.1 kg block slides with a speed of 1.1 m/s on a frictionless, horizontal surface until it encounters a spring. (a) If the block compresses the spring 5.7 cm before coming to rest, what is the force constant of the spring? (b) What initial speed should the block have to ...
*March 29, 2010 by Carden*

**Physics, please help**

Hello, I don't know how about to answering this question: work out the problem of a ball of mass m that falls a distance h from rest. It hits the floor and rebounds to its starting height. (a) What total time ie required for the motion? (Neglect the time of contact with the ...
*October 31, 2006 by amber*

**physics**

2 waves are traveling through a container of nitrogen gas. Amplitude of the first wave is 0.3 cm, and the second 0.9 cm. What is true about the two waves? a. the energy of thee first wave is less than the second b. energy of the first wave is greater c. speed of the first wave...
*February 23, 2010 by Toni*

**physics**

The 1994 Winter Olympics included the aerials competition in skiing. In this event skiers speed down a ramp that slopes sharply upward at the end. The sharp upward slope launches them into the air, where they perform acrobatic maneuvers. In the women's competition, the end of ...
*October 24, 2010 by myx*

**Physics**

The 1994 Winter Olympics included the aerials competition in skiing. In this event skiers speed down a ramp that slopes sharply upward at the end. The sharp upward slope launches them into the air, where they perform acrobatic maneuvers. In the women's competition, the end of ...
*July 9, 2011 by Kristi*

**Physics**

The 1994 Winter Olympics included the aerials competition in skiing. In this event skiers speed down a ramp that slopes sharply upward at the end. The sharp upward slope launches them into the air, where they perform acrobatic maneuvers. In the women's competition, the end of ...
*June 27, 2012 by Emily*

**Physics**

The 1994 Winter Olympics included the aerials competition in skiing. In this event skiers speed down a ramp that slopes sharply upward at the end. The sharp upward slope launches them into the air, where they perform acrobatic maneuvers. In the women's competition, the end of ...
*September 18, 2012 by Donald*

**Math for Liberal Arts**

Directions: Define the necessary symbols, rewrite the argument in symbolic form, and us a truth table to determine whether the argument is valid. If the argument is invalid, interpret the specific circumstances that cause the argument to be invalid. Problem: 1. If you argue ...
*November 8, 2012 by Dawn*

**Physics**

A 10 kg crate is pulled up a rough incline with an initial speed of 1.5 m/s. The pulling force is 86 N parallel to the incline, which makes an angle of 30 ° with the horizontal. Assuming the coefficient of kinetic friction is 0.4 and the crate is pulled a distance of 7.5 mfind...
*January 5, 2011 by Bob*

**physics pls help**

A sound source producing 1.00-{\rm kHz} waves moves toward a stationary listener atone-half the speed of sound. The frequency that the listener will hear is2000 Hz. when the source is stationary and the listener moves towardthe source at one-half the speed of sound, the ...
*June 28, 2011 by dan pogi*

**Physics**

A tractor of mass 5.0*10^3kg is used to tow a car of mass 2.5*10^3kg.the tractor moved with a speed of 3.0m/s^1 just before the towing rope became taut.calculate:the speed of the tractor immediately the rope became taut, loose kinetic energy of the system just after the car ...
*January 30, 2012 by Thank-God*

**Physics Help!!!!!!!!!!!!!!!!**

Suppose you were asked to develop a concept of "automobile current" ( a current formed by moving cars) for traffic on an interstate or busy street near you. a) what would be the units of "automobile current"? b) what info would be the "automobile current" provide? c) explain ...
*February 11, 2015 by Urgent Help *

** Advanced Maths (Vectors) AQA Level**

A boat which can travel at 5m/s in still water is crossing a river 200 m wide.the rate of the flow of the river is 2 m/s assumed uniform at every point in the river. Point A and B are directly opposite to each other across the river. a) If the boat leaves A and steer towards B...
*February 21, 2012 by Jat*