Saturday

May 23, 2015

May 23, 2015

Number of results: 21,964

**physics**

A,1.5kg,object,moves,up,the,y,axis,at,a,constant,speed.When,it,reaches,the,origin,the,force,F1=5.0N,at,37,deg,above,the,+x,axis,F2,=2.5N,in,the,+x,direction,F3=,3,5N,at,45,deg,below,the,neg,x,axis,and,F4,=,1.5N,in,the,neg,y,direction,are,applied,to,it,(a)Will,the,object,...
*January 19, 2008 by melissa*

**physics**

Gayle runs at a speed of 8.00 m/s and dives on a sled, initially at rest on the top of a frictionless, snow-covered hill, that has a vertical drop of 14.0 m. After she has descended a vertical distance of 5.00 m, her brother, who is initially at rest, hops on her back, and ...
*October 21, 2012 by Anonymous*

**science**

The speed of a bullet as it travels down the barrel of a rifle toward the opening is given by v = (-4.25 10^7) t^2 + (3.45 10^5) t, where v is in meters per second and t is in seconds. The acceleration of the bullet just as it leaves the barrel is zero. (a) Determine the ...
*January 22, 2015 by Anonymous*

**Centrifulag pump curve**

Q4 The system on site is a pressure sand filter, with a service curve. The filter is backwashed using the feed pump, at a higher flow rate, shown as backwash curve. Service duty point : 3 m3/h Backwash duty point : 9 m3/h Part (a) (4 marks) What is the speed of the pump to ...
*January 29, 2014 by Tony*

**Physics**

A car is doing a loop-the-loop. The loop has a radius of .4m. Assume the car is starting with the minimum speed it needs in order to stay in contact with the track at all times (at the top of the track, the car is not applying a force to the track). neglect friction. What is ...
*March 6, 2012 by Melissa*

**Math**

If it takes 6 minutes to travel from point A to point B at a constant speed of 60 miles per hour, how many minutes does it take to travel the same route from point A to point B at a constant speed of 50 miles per hour?
*July 11, 2012 by Samantha*

**Math**

If 60 miles per hour is equivalent to a speed of 88 feet per second, express a speed of 45 miles per hour in feet per second. feet/sec
*May 18, 2008 by Mike*

**physics**

A 0.59 kg rubber ball has a speed of 1.50 m/s at point A and kinetic energy of 7.0 J at point B. (a) Determine the ball's kinetic energy at A Correct: Your answer is correct. J (b) Determine the ball's speed at B
*December 3, 2014 by kelly*

**physics**

hi,need help please.thank. A car is designed to get its energy from a rotating flywheel (solid disk) with a radius of 2.00 m and a mass of 525 kg. Before a trip, the flywheel is attached to an electric motor, which brings the flywheel's rotational speed up to 4000 rev/min. (a...
*November 22, 2009 by Chan*

**physics**

In outer space two identical space modules are joined together by a 500.0 massless cable. These modules are rotating about their center of mass. In each module, the cable is connected to a motor,so that the modules can pull each other together. The initial tangential speed of ...
*June 2, 2011 by Samantha*

**phys2**

A 60-kg astronaut is in space, far from any objects that would exert a significant gravitational force on him. He would like to move toward his spaceship, but his jet pack is not functioning. He throws a 720-g socket wrench with a velocity of 5 m/s in a direction away from the...
*March 17, 2012 by opp*

**nova**

7) You throw a 12-N stone vertically into the air from ground level. You observe that when it is 15.0 m above the ground, it is traveling at 25.0 m/s upward. Use the work –energy theorem to find (a) the stone’s speed just as it left the ground and (b) its maximum height. 8) A ...
*September 20, 2014 by papy*

**Physics**

A small block on a frictionless horizontal surface has a mass of 2.50×10−2 Kg. It is attached to a massless cord passing through a hole in the surface. The block is originally revolving at a distance of 0.300 m from the hole with an angular speed of 1.75 rad/s. The cord ...
*November 7, 2007 by Christina*

**Physics**

A missile launcher, mass M, at rest on a horizontal track fires a missile, mass m, horizontally. a) If the launch speed of the missile is v o , what (effective) coefficient of (kinetic) friction is required in order to stop the launcher within x meters? (b) Missile launcher ...
*August 8, 2012 by Chad*

**Physics**

A missile launcher, mass M, at rest on a horizontal track fires a missile, mass m, horizontally. a) If the launch speed of the missile is v o , what (effective) coefficient of (kinetic) friction is required in order to stop the launcher within x meters? (b) Missile launcher ...
*August 7, 2012 by Chad*

**mechanics**

Q3. A skeet (a small disc) of massM is fired at an angle to the horizontal with a speed v0. When it reaches the maximum height it is hit from below by a pellet of mass m (m < M) traveling vertically upward at a speed of v. The pellet is embedded in the skeet. (a) What is ...
*December 9, 2010 by sana*

**physics waves transverse longitudinal**

i real stuck on this and i really want explanations please. in which sprind do transverse waves travel faster, small diameter spring or slinky? i think this be the transverse waves but i not know how to explain why. in which spring do longitudinal waves travel faster? i think ...
*January 9, 2012 by Shreya*

**Physics (Algebra-based)**

A block starts at rest and slides down a frictionless track except for a small rough area on a horizontal section of the track.It leaves the track horizontally, flies through the air, and subsequently strikes the ground. gravity= 9.81 m/s^2. height1=4.1m---- is initially ...
*April 6, 2013 by Becky*

**Health**

Justine would like to improve her speed while dribbling the soccer ball from the defensive to the offensive side of the field. Justine can develop her speed for this type of activity by practicing · moving the ball close to her foot with control from one end of the field to ...
*December 31, 2013 by Steve*

**Physics**

Under what conditions can a quadratic function be a perfect square? Also.. A stone is thrown vertically upward at a speed of 40m/s. How long does it take to reach a height of 90m? I ended up with a quadratic of t^2-8t+18 which cannot be factored...So is the answer that the ...
*February 19, 2008 by Anonymous*

**Physics**

Under what conditions can a quadratic function be a perfect square? Also.. A stone is thrown vertically upward at a speed of 40m/s. How long does it take to reach a height of 90m? I ended up with a quadratic of t^2-8t+18 which cannot be factored...So is the answer that the ...
*February 19, 2008 by Anonymous*

**physics**

A child in danger of drowning in a river is being carried downstream by a current that has a speed of 2.10 km/h. The child is 0.600 km from shore and 0.800 km upstream of a boat landing when a rescue boat sets out. (a) If the boat proceeds at its maximum speed of 19.0 km/h ...
*October 28, 2012 by anusha*

**physics**

A mass m = 11.0 kg rests on a frictionless table and accelerated by a spring with spring constant k = 4979.0 N/m. The floor is frictionless except for a rough patch. For this rough path, the coefficient of friction is μk = 0.46. The mass leaves the spring at a speed v = 2...
*September 28, 2012 by hater of physics*

**Algebra I**

1. A Passenger train's speed is 60mi/h and a freight train's speed is 40mi/h. The passenger train travels the same distance in 1.5 h less time than the freight train. How long does each train take to make the trip? 2. Lois rode her bike to visit a friend. She traveled at 10 mi...
*October 9, 2007 by Wilford*

**Algebra 2**

how would you solve: the current in the river flowed at 3 mph. The boat could travel 24 mph downstream in half the time it took to travel 12 mi upstream. what was the speed of the boat in still water? please help. The time required to go any distance upstream a distance L is L...
*June 18, 2006 by Jonathan*

**Chem**

For a photon with = 730 nm, determine its speed, frequency, energy, and color. For frequency the formula would be v=c/lambda 3.00x10^8/7.30x10^-7=2.19x10^14/s Speed c=(v)(lambda) C=(v)(lambda) C= (2.19x10^14/s)(1.37x10^-6)=3.00x10^8 I got the wavelength by doing the ...
*October 25, 2014 by Feather*

**physics**

(Requires calculus) Prove the relativistic work-energy theorem in one dimension. The force exerted on a particle is given not by F=ma, but F=dp/dt. Using the expression for the relativistic momentum of a particle p=γmv, integrate the force exerted on the particle over the...
*September 26, 2009 by kkke*

**Physics**

1.You are stuck on a cliff and want to know how far to the bottom. You drop a rock and time how long it takes to hit the ground. If the rock takes 10 seconds to hit the ground how high is the cliff? How fast was the rock going to impact? 2. You throw a plate off your roof with...
*March 22, 2012 by Anonymous*

**Physics Probelms ASAP**

Could you please check my work and help me with a couple. An airplane that flies at 100 km/h with a 10 km/h tailwind travels at 110 km/h relative to the ground. If it instead flies into a 10 km/h headwind, its groundspeed is : 110 km/h /2= 55 km/h The average speed of a horse ...
*August 29, 2007 by Soly*

**Physics**

A 250 g block is dropped onto a relaxed veritcal spring that has a spring constant of k=2.5 N/cm. The block becomes attached to the spring and compresses the spring 12 cm befor momentarily stopping. While the spring is being compressed, what work is done on the block by a) ...
*December 16, 2006 by Me*

**physics**

Cars A and B are racing each other along the same straight road in the following manner: Car A has a head start and is a distance Da beyond the starting line at t=0. The starting line is at x=0. Car A travels at a constant speed Va. Car B starts at the starting line but has a ...
*June 30, 2011 by mjLa*

**Math**

The average student enrolled in the 20-wk Court Reporting I course at the American Institute of Court Reporting progresses according to the rule below where 0 t 20, and N'(t) measures the rate of change in the number of words/minute dictation the student takes in machine ...
*April 9, 2014 by Vanessa*

**physics**

A disk of mass m is spinning freely at 6.22 rad/s when a second disk of identical mass, initially not spinning, is dropped on it so that their axes coincide. In a short time the two disks are corotating. (The two disks have the same radius.) (a) What is the angular speed of ...
*March 6, 2015 by alba*

**Physics Equations of Motion**

Along a straight road through town, there are three speed-limit signs. They occur in the following order: 66 , 31 , and 19 mi/h, with the 31 -mi/h sign located midway between the other two. Obeying these speed limits, the smallest possible time tA that a driver can spend on ...
*June 7, 2012 by Jackie*

**Physics**

A river has a steady speed of 0.500 m/s.A student swims upstream a distane of 1.00 km and swims back to the starting point. If the student can swim at a speed of 1.20 m/s in still water, how long does the trip take? How much time is required in still water for the same length ...
*February 13, 2014 by Anonymous*

**math Help ASAP**

write and solve inequality 17. the speed limit of a highway is 55 miles per hour. a car is traveling at least 65 miles per hour. how many miles per hour m over the speed limit is the car traveling? A 55-m>equal to 65;m. eqaul to 10 B m+65< equal to 55; m < equal to -...
*October 21, 2014 by kathy *

**physics**

A 10000 car comes to a bridge during a storm and finds the bridge washed out. The 700 driver must get to the other side, so he decides to try leaping it with his car. The side the car is on is 24.0 above the river, while the opposite side is a mere 6.80 m above the river. The ...
*February 11, 2008 by samantha*

**Physics**

I listed the questions with my answers. Are the answers correct? Thanks. A railroad locomotive is a rest with its whistle shrieking, and then it starts moving toward you. a.) Does the frequency that you hear increase, decrease, or stay the same? The frequency of the waves ...
*October 17, 2009 by Mary*

**physics**

a shopper in a supermarket pushes a cart with a force of 35 n directed at an angle of 25 downward from the horizontal. the force is just sufficient to over come the various frictional force, so the cart moves at constant speed. what is the net work dont on the cart? why? the ...
*September 23, 2010 by physics help please!!!*

**Astrophysics**

You know M(r) = v^2r /G d = distance; s= speed Planet 1: d=2/s=120 Planet 2: d=4/s=60 Planet 3: d=9/s=40 Planet 4: d=16/s=30 Planet 5: d=36/s = 20 You use the distance and orbital speed of the first planet to determine the mass enclosed within the orbit of the first planet to ...
*October 29, 2008 by anonymous*

**Physics**

An open-topped tank completely filled with water has a release valve near its bottom. The valve is 1.75m below the water surface. Water is released from the valve to power a turbine, which generates electricity. The area of the top of the tank, AT, is 11.5 times the cross-...
*September 3, 2014 by Santi*

**physics**

The speed of a bullet as it travels down the barrel of a rifle toward the opening is given by v = (-4.25 107) t 2 + (3.45 105) t, where v is in meters per second and t is in seconds. The acceleration of the bullet just as it leaves the barrel is zero. (a) Determine the ...
*January 22, 2015 by Anonymous*

**physics**

A bullet with mass m = 5.21 g is moving horizontally with a speed v=367 m/s when it strikes a block of hardened steel with mass M = 14.8 kg(initially at rest). The bullet bounces o the block in a perfectly elastic collision. (a) What is the speed (m/s) of the block immediately...
*December 15, 2011 by Sarah*

**physics**

Traffic shock wave. An abrupt slowdown in concentrated traffic can travel as a pulse, termed a shock wave, along the line of cars, either downstream (in the traffic direction) or upstream, or it can be stationary. Figure 2-22 shows a uniformly spaced line of cars moving at ...
*October 10, 2011 by turk*

**physics i really need help :(**

A projectile is fired with an initial speed of 61.3m/s at an angle of 31.5° above the horizontal on a long flat firing range. a)Determine the maximum height reached by the projectile. b)Determine the total time in the air. c)Determine the total horizontal distance covered (...
*November 24, 2012 by juanita*

**physics**

Two gears A and B are in contact. The radius of gear A is twice that of gear B. (a) when A’s angular velocity 6.00 Hz counter clockwise, what is B’s angular velocity? (b) If A’s radius to the tip of the teeth is 10.0 cm what is the linear speed of a point on the tip of a gear ...
*October 3, 2011 by John*

**math**

Two towns P and Q are 400 km apart. A bus left for P and Q. It stopped at Q for one hour and then started the return to P. one hour after the departure of the bus from P, a trail also heading for Q left P. the trailer met the returning bus ¾ of the way from P to Q. they met t ...
*March 14, 2015 by kudu*

**math**

Two towns P and Q are 400 km apart. A bus left for P and Q. It stopped at Q for one hour and then started the return to P. one hour after the departure of the bus from P, a trail also heading for Q left P. the trailer met the returning bus ¾ of the way from P to Q. they met t ...
*March 15, 2015 by kudu*

**general science**

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 26, 2010 by Mike*

**physics help**

A 1100 kg automobile is at rest at a traffic signal. At the instant the light turns green, the automobile starts to move with a constant acceleration of 3.0 m/s2. At the same instant a 2800 kg truck, traveling at a constant speed of 8.0 m/s, overtakes and passes the automobile...
*March 26, 2010 by beav*

**Physics - sound waves**

I listed the questions with my answers. Are the answers correct? Thanks. A railroad locomotive is a rest with its whistle shrieking, and then it starts moving toward you. a.) Does the frequency that you hear increase, decrease, or stay the same? The frequency of the waves ...
*October 17, 2009 by Mary*

**Math**

The Pioneer 10 spacecraft passed the planet Jupiter on December 12, 1973, and exited the solar system on June 14, 1983. The craft traveled from Mars to Jupiter, a distance of approximately 1 billion kilometers, in one year and nine months. a.Calculate the approximate speed of ...
*November 17, 2013 by Aubrey*

**Displacement and Velocity**

A turtle moves 3.5m [E] in 136 s and then moves 1.7m [W] in 88 s. a) What is the average speed of the turtle? b) What is the average velocity of the turtle? average speed: D/T = 3.5m + 1.7m = 5.2m/ 224s = 0.024m/s average velocity:??????????/
*November 13, 2010 by Anonymous*

**Physics**

Two pucks collide on a level air-hockey table. Puck A has a mass of 0.0250 kg and is moving initially due eastward at a speed of 5.50m/s. Puck B has a mass of 0.0500kg and is initially at rest. Right after collision, puck A is moving in a direction of 65 degrees north of east...
*November 2, 2009 by John*

**Physics**

A 15.0 m long truck traveling at 40.0 mph has a braking capability of 5.00 m/s2 from this speed. It is approaching a 10.0-m wide intersection with a traffic light that is turning yellow. (a) What is the minimum distance the truck can be from the intersection if the truck is to...
*January 23, 2013 by Help Me*

**Physics Help Please**

Suppose you work at an amusement park. Your boss has asked you to determine the "people current," a measurement of moving people coming through the entrance of the park. a) what would be the units of "people current?" b) what information would "people current" provide? c) ...
*February 11, 2015 by Help!*

**Physics Help Please!**

Suppose you work at an amusement park. Your boss has asked you to determine the "people current," a measurement of moving people coming through the entrance of the park. a) what would be the units of "people current?" b) what information would "people current" provide? c) ...
*February 11, 2015 by Help!*

**Physics**

A man stands on a platform that is rotating (without friction) with an angular speed of 1.21 rev/s; his arms are outstretched and he holds a brick in each hand The rotational inertia of the system consisting of the man, bricks, and platform about the central axis is 4.32 kg·m2...
*November 18, 2011 by Aimee*

**physics**

A 120 kg mass is blown apart into an 80 kg piece and 40 kg piece. after the blast, the two masses are moving apart with a relative velocity of 60 m/s. the total kinetic energy after the explosion is: A. 21 kJ B. 35 kJ C. 48 kJ D. 56 kJ E. 82 kJ Because of momentum conservation...
*August 6, 2007 by mandy*

**Physics 141**

A satellite is in a circular orbit around an unknown planet. The satellite has a speed of 1.60 104 m/s, and the radius of the orbit is 5.50 106 m. A second satellite also has a circular orbit around this same planet. The orbit of this second satellite has a radius of 8.50 106 ...
*February 21, 2014 by Hope*

**Physics 141**

A satellite is in a circular orbit around an unknown planet. The satellite has a speed of 1.60 104 m/s, and the radius of the orbit is 5.50 106 m. A second satellite also has a circular orbit around this same planet. The orbit of this second satellite has a radius of 8.50 106 ...
*February 21, 2014 by Hope*

**Physics**

In this section assume the sound speed in air is 343 m/s. A goose flying toward you at 12.6m/s emits a squawk, which you hear at 258Hz . A)Find the wavelength of the sound you hear B)Find the wavelength of the sound you hear if the goose emits the same squawk while flying away...
*December 2, 2013 by sandra*

**Physics**

With what speed relative to the rocks does the clam smash into the rocks? and With what speed relative to the gull does the clam smash into the rocks?
*September 20, 2012 by Lisa*

**Physics**

A stone is thrown from the edge of a cliff into the ocean below. It is thrown somewhat upward, but mostly outward. The stone has a mass of 2.0kg and is thrown with a speed of 10m/s from an initial height of 5.0m above the ocean. A. What is the kinetic energy of the stone when ...
*April 1, 2013 by Jay*

**Physics**

A stone is thrown from the edge of a cliff into the ocean below. It is thrown somewhat upward, but mostly outward. The stone has a mass of 2.0kg and is thrown with a speed of 10m/s from an initial height of 5.0m above the ocean. A. What is the kinetic energy of the stone when ...
*April 1, 2013 by Jay*

**Physics**

A hare and a tortoise compete in a race over a course 1.20 km long. The tortoise crawls straight and steadily at its maximum speed of 0.540 m/s toward the finish line. The hare runs at its maximum speed of 9.00 m/s toward the goal for 0.800 km and then stops to taunt the ...
*October 9, 2009 by Chloe*

**physics**

A hare and a tortoise compete in a race over a course 4.90 km long. The tortoise crawls straight and steadily at its maximum speed of 0.440 m/s toward the finish line. The hare runs at its maximum speed of 14.00 m/s toward the goal for 0.800 km and then stops to tease the ...
*September 9, 2012 by Kit*

**physics**

police officer in a patrol car parked in a 70km/h zone observe a passing automobile travelling at a slow. constant speed. believing that of the automobile might be intoxicated the officer starts his car acceleration uniformly to 9km/h in 8s. and maintaining a constant velocity...
*October 17, 2013 by abdul*

**math-word problem**

A plane flies with a ground speed of 160 miles per hour if there is no wind. It travels 350 miles with a head wind and in the same time it takes to go 450 miles with a tail wind. Find the speed of the wind. I'm pretty bad with word problems, but this is how I answered it: set ...
*May 6, 2008 by Jennifer*

**Physics**

To stop a car, you require first a certain reaction time to begin braking. Then the car slows under the constant braking deceleration. Suppose that the total distance moved by your car during these two phases is 56.7 m when its initial speed is 80.0 km/h, and 24.4 m when the ...
*October 3, 2010 by Bob*

**Physics ~ CONSERVATION OF MOMENTUM~**

1.) A 10,000 kg railroad car traveling at a speed of 24.0 m/s strikes an identical car at rest. If the cars lock together as a result of the collision, what is their common speed afterward? 2.) A 3.0 kg ball at 3 m/s and strikes a 1.5 kg ball moving at -2 m/s. After the ...
*February 18, 2013 by Isis*

**Physics **

A train traveling at a speed of 110 km/h uniformly decelerates for 20 seconds. During that time it travels 450m. A) What is the acceleration? (m/s^2) B) What is its speed after deceleration? (km/h) A ANS = -.805m/s^2 B ANS = 52km s = 450m t = 20 seconds u = 110km/h*1000m/km /...
*January 11, 2014 by Danny*

**Calculus**

Astronomers have a mathematical model for the orbital speed of the stars as a function of their distance x from the center of the galaxy: V(x) = 350x/(1+(x^2))^(3/4) where x = 1 for 10,000 light years, x = 2 for 20,000 light years. At a distance of 10,000 light years, the ...
*January 24, 2012 by Scooby10*

**physics**

Two stones, A and B, are thrown horizontally from the top of a cliff. Stone A has an initial speed of 15 meters per second and stone B has an initial speed of 30 meters per second. Compared to the time it takes stone A to reach the ground, the time it takes stone B to reach ...
*November 18, 2013 by Anonymous*

**physics**

A house with its own well has a pump in the basement with an output pipe of inner radius 6.4 mm. Assume that the pump can maintain a gauge pressure of 420 kPa in the output pipe. A showerhead on the second floor (7.5 m above the pump's output pipe) has 38 holes, each of radius...
*April 9, 2012 by Angelina*

**physics**

In a World Cup soccer match, Juan is running due north toward the goal with a speed of 7.80 m/s relative to the ground. A teammate passes the ball to him. The ball has a speed of 13.6 m/s and is moving in a direction of 32.5 degrees east of north, relative to the ground. a)...
*November 2, 2010 by bobjahng*

**physics**

An ice skater spins about a vertical axis at an angular speed of 15 rad s−1 when her arms are outstretched. She then quickly pulls her arms into her sides in a very small time interval so that the frictional forces due to ice are negligible. Her initial moment of inertia...
*March 15, 2012 by swapnali*

**physics**

A certain truck can slow at a maximum rate of 4.6 m/s2 in an emergency. When traveling in this truck at a constant speed of 19 m/s the driver spots a large hole in the road 48.2 m in from of his position. The truck continues moving forward at a constant speed until the driver ...
*September 22, 2013 by lanaaaaaa*

**science**

A gear with 30 teeth turns a gear with 5 teeth. How many turns will the driven gear turn for every turn the drive gear makes? Is this type of gear train usedto increase force or speed and distance? The tumber of teeth engaged is the same for both gears, but 30 teeth (1 turn) ...
*March 27, 2007 by kelly5*

**physics college**

An antelope moving with constant acceleration covers the distance between two points 70.0 m apart in 7.00 s. Its speed as it passes the second point is 15.0 m/s. (a) What is its speed at the first point? (b) What is its acceleration? A car is stopped at a traffic light. It ...
*October 8, 2010 by meera*

**PHYSICS**

A roller coaster powered by a spring launcher follows a frictionless track as shown below. The roller coaster cart has a mass of 500 kg, and the spring launcher has a spring constant of 1500 N/m. a. If the cart starts at a height h1 = 10m, how much must the spring be ...
*February 12, 2014 by Sarah*

**physics **

A race car is able to accelerate at a rate of 14m/s2. After exiting a turn at a speed of 15m/s, the car enters a straightaway and accelerates to a speed of 96m/s just as it reaches the end of the straightaway and enters the next turn. A)how long did it take the car to ...
*July 18, 2011 by Edward*

**Physics**

Jack and Jill are skating. Jill has a mass of 50 kg, Jack has a mass of 80 kg. At t=0 seconds Jill starts skating across a 50 m diameter rink at a speed of 3 m/s. After 3 seconds Jack skates after her with a speed of 5 m/s. When they meet, Jack scoops up Jill and they glide to...
*May 13, 2013 by Hale*

**math**

One train left the station and traveled toward its destination at a speed of 65 miles per hour. Later, another train left the station traveling in the opposite direction of the first train, it was going at a speed of 75 miles per hour. After the first train had traveled for 14...
*May 23, 2013 by jake*

**physics**

A uranium nucleus 238U may stay in one piece for billions of years, but sooner or later it decays into an a particle of mass 6.64×10^−27 kg and 234Th nucleus of mass 3.88 × 10^−25 kg, and the decay process itself is extremely fast(it takes about 10^−20 s). ...
*January 16, 2010 by Anonymous*

**physics**

Two tanks are engaged in a training exercise on level ground. The first tank fires a paint-filled training round with a muzzle speed of 250 m/s at 10.0◦ above the horizontal while advancing toward the second tank with a speed of 15.0 m/s relative to the ground. The ...
*October 5, 2014 by Anonymous*

**math**

At an airport, a flight controller was in a tower 40m above the ground. When she first observed a plane it was at an angle of elevation of 12 (degrees) from her line of sight and flying at a constant altitude (height) The plane had a constant speed of 360km/h Eight seconds ...
*May 19, 2013 by alice*

**Physics**

A truck on a straight road starts from rest and accelerates at 2.8 m/s^2 until it reaches a speed of 16 m/s. Then the truck travels for 16s at constant speed until the brakes are applied,stopping the truck in a uniform manner in an additional 3.6 s. How long is the truck in ...
*September 9, 2014 by Isaac*

**physics**

A person is riding on a flatcar traveling at a constant speed v1= 15 m/s with respect to the ground. He wishes to throw a ball through a stationary hoop in such a manner that the ball will move horizontally as it passes through the hoop. The hoop is at a height h=4 m above his...
*October 4, 2013 by leonard*

**physics**

Two arrows are shot vertically upward. The second arrow is shot after the first one, but while the first is still on its way up. The initial speeds are such that both arrows reach their maximum heights at the same instant, although these heights are different. Suppose that the...
*August 26, 2012 by Anonymous*

**Physics**

Two arrows are shot vertically upward. The second arrow is shot after the first one, but while the first is still on its way up. The initial speeds are such that both arrows reach their maximum heights at the same instant, although these heights are different. Suppose that the...
*August 31, 2012 by Marissa*

**physics**

Two arrows are shot vertically upward. The second arrow is shot after the first one, but while the first is still on its way up. The initial speeds are such that both arrows reach their maximum heights at the same instant, although these heights are different. Suppose that the...
*September 5, 2012 by Tracie *

**physics**

A 316-kg boat is sailing 12.0° north of east at a speed of 1.60 m/s. 39.0 s later, it is sailing 36.0° north of east at a speed of 4.00 m/s. During this time, three forces act on the boat: a 31.4-N force directed 12.0° north of east (due to an auxiliary engine), a 20.7-N force...
*September 14, 2012 by marissa*

**physics**

A collision occurs between two pucks on an air-hockey table. Puck A has a mass of 0.020 kg and is moving along the x axis with a velocity of +5.5 m/s. It makes a collision with puck B, which has a mass of 0.040 kg and is initially at rest. The collision is not head-on. After ...
*January 13, 2013 by Miranda*

**Physics**

In order to convert a tough split in bowling, it is necessary to strike the pin a glancing blow as shown in Fig. 9-47. The bowling ball, initially traveling at 13.0 m/s, has four times the mass of a pin and the pin flies off at 80° from the original direction of the ball. ...
*March 5, 2014 by Anonymous*

**physics**

A 800·kg elevator is attached to a cable whose tension is 7800·N. Which of the following statements could describe the motion of the elevator? Choose all that apply. slowing down as it moves upward moving upward at constant speed speeding up as it moves downward slowing down ...
*January 17, 2013 by wally*

**Physics HELP!**

A war-wolf, or trebuchet, is a device used during the Middle Ages to throw rocks at castles and now sometimes used to fling pumpkins and pianos. A simple trebuchet is shown in the figure. Model it as a stiff rod of negligible mass 3.00 m long and joining particles of mass 74....
*November 6, 2012 by Holly*

**Math**

For one pony, thecritical force was 1.16 times its body weight. It experienced a force of 0.75 times its body weight at a speed of 2 meters per second, and a force of 0.93 times its body weight at 3 meters per second. At what speed did the pony switch from a trot to a gallop? ...
*January 26, 2012 by Aryan*

**ap chem0 frequency**

how do u do this type of problem... What is the frequency of a photon with a wavelength of 2.25 102 nm? (The speed of light in a vacuum is 2.998 108 m/s. Planck's constant is 6.626 10-34 Js c = fw. c is speed of light which you have, f is frequency for which you must solve, w ...
*September 28, 2006 by ash*

**PHYSICS--SHM**

PLZ HELP. THANKS. The balance wheel of a watch oscillates with an angular amplitude of rad and a period of 0.220 s. a) Find the maximum angular speed of the wheel. (b) Find the angular speed of the wheel when its displacement is /4 rad. (c) Find the magnitude of the angular ...
*January 27, 2007 by wooh*