Number of results: 26,021

**Math**

Mrs Leong took 1 hour to drive 1/5 of a journey from village R to village S.she drove the remaining 180km in 4hr. A) what was Mrs Leong's speed for the first part of the journey? B) how long did she take to travel the whole journey? C) find Mrs Leong's average speed for the ...

*March 26, 2012 by Da S*

**Physics**

A 4kg box is attached to a 2.4m rope rotating on platform. Max tension can withstand without breaking is 140N. 1.) Find Max. speed w/ which the box can rotate if the surface of platform is frictionless. 2.) Find Max speed w/ which box can rotate if Coeff. of friction between ...

*March 17, 2016 by Kelly*

**science-physics**

A swimmer, capable of swimming at a speed of 1.97 m/s in still water (i.e., the swimmer can swim with a speed of 1.97 m/s relative to the water), starts to swim directly across a 2.77-km-wide river. However, the current is 1.13 m/s, and it carries the swimmer downstream. (a) ...

*October 7, 2012 by pd*

**Physics**

A stone is dropped from rest from the roof of a 100-m high building; 2.00 s after that, a second stone is thrown straight down with initial speed v0, and the second stone passes the first stone 21.6 m above ground. (a) When are the stones at the same height? (b) What was the ...

*January 23, 2013 by Help Me*

**Physics**

A swimmer, capable of swimming at a speed of 1.44 m/s in still water (i.e., the swimmer can swim with a speed of 1.44 m/s relative to the water), starts to swim directly across a 2.21-km-wide river. However, the current is 0.840 m/s, and it carries the swimmer downstream. (a) ...

*September 28, 2014 by Ashley*

**PHYSICS**

A swimmer, capable of swimming at a speed of 1.24 m/s in still water (i.e., the swimmer can swim with a speed of 1.24 m/s relative to the water), starts to swim directly across a 2.24-km-wide river. However, the current is 0.553 m/s, and it carries the swimmer downstream. (a) ...

*March 27, 2015 by Physics2hard4me*

**science**

an electron is projected horizontally at a speed of 3x10^6 m/s into a uniform electric field 200 N/C produced by two charged plates of width 0.1m (a) find the a cceleration of the electron in the elec field.(b) finn the time takes to travel through the electric field.(c) what ...

*February 24, 2017 by rahidul*

**physics**

An electron is projected horizontally at a speed of 3x10^6 m/s into a uniform electric field 200 N/C produced by two charged plates of width 0.1m (a) find the a cceleration of the electron in the elec field.(b) finn the time takes to travel through the electric field.(c) what ...

*February 24, 2017 by rahidul*

**Physics**

At t = 0, an automobile traveling north begins to make a turn. It follows one-quarter of the arc of a circle of radius 10.9 m until, at t = 1.56 s, it is traveling east. The car does not alter its speed during the turn. Find the car's speed. Find the change in its velocity ...

*February 7, 2010 by Max*

**physics**

At t = 0, an automobile traveling north begins to make a turn. It follows one-quarter of the arc of a circle of radius 9.3 m until, at t = 1.38 s, it is traveling east. The car does not alter its speed during the turn. (a) Find the car's speed. (b) Find the change in its ...

*February 14, 2010 by candace*

**physics**

At t = 0, an automobile traveling north begins to make a turn. It follows one-quarter of the arc of a circle of radius 10.1 m until, at t = 1.64 s, it is traveling east. The car does not alter its speed during the turn. (a) Find the car's speed. (b) Find the change in its ...

*January 28, 2014 by Colin*

**Physics**

A police car stopped at a set of lights has a speeder pass it at 100 km/h. If the police car can accelerate at 3.6 m/s2, a) how long does it take to catch the speeder? b) how far would the police car have to go before it catches the speeder? c) what would its speed be when it ...

*April 21, 2014 by Alex*

**physics**

The pulley in the figure represents different pulleys with outer radius and inner radius indicated in the table. The horizontal rope is pulled to the right at a constant speed that is the same in each case, and none of the ropes slips in its contact with the pulley Rank these ...

*August 8, 2011 by help123*

**physic**

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 23, 2009 by Chan*

**pre calc**

I am sooo confused on my homework. #1 Two cars lave an intersection at the same time. One is headed south at a constant speed of 30mph. the other is heading west at a constant speed of 40mph. Build a model that expresses the distance (d) between thec ars as a funtion of time (...

*September 18, 2012 by Rebekah*

**Physics 12**

This came up on our test review for tomorrow, and I'm stumped! "A hockey puck of mass 0.51 kg is moving north across the ice with a speed of 32 m/s. If it is hit with a hockey stick so as to make it travel due west at the same speed, what is the magnitude of the impulse ...

*October 28, 2008 by solexgirl12*

**Physics please help**

TIgers pitcher justin throws a basketball staright upward 29.0m/s. Calculate A) the height to which the ball will rise b) the time it takes to reach the highest point c) the speed with which it will return to the same height which it was thrown d) the speed of the ball 2.50s ...

*December 20, 2014 by unknown*

**Precalculus**

I tried doing this problem, but I still don't understand it at all... Pilot Reem Ahmad's flight plan has her leaving Dulles International Airport and flying a Boeing 727 due east at 450 mph. There is a 65 mph wind with the bearing 60 degrees. a. Determine the compass heading ...

*February 3, 2010 by Marie*

**physics**

Small, slowly moving spherical particles experience a drag force given by Stokes’ law: where r is the radius of the particle, is its speed, and η is the coefficient of viscosity of the fluid medium. (a) Estimate the terminal speed of a spherical pollution particle of ...

*February 19, 2010 by katie*

**physics**

Small, slowly moving spherical particles experience a drag force given by Stokes’ law: where r is the radius of the particle, is its speed, and η is the coefficient of viscosity of the fluid medium. (a) Estimate the terminal speed of a spherical pollution particle of ...

*February 19, 2010 by mike*

**Physics**

A flute is designed to play middle C (262 Hz) as the fundamental frequency when all the holes are covered. The length of the flute is 0.655 m. Assume the air temperature is 20°C. How far from the end of the flute should the hole be that must be uncovered to play F above ...

*May 31, 2010 by Luricela*

**Physics**

An observer stands 43.0 m behind a marksmen practicing at a rifle range. The marksman fires the rifle horizontally which gives the speed of the bullet to be 939 m/s. How far does each bullet travel before the observer hears the report of the rifle? Assume that the bullet ...

*March 13, 2011 by Steph*

**Physics Conducting Spheres**

1. Two concentric conducting spherical shells have radii of 0.145 m. and 0.215 m. The inner sphere bears a charge of -3.00E-08 C. An electron escapes from the inner sphere with negligible speed. Assuming that the region between the spheres is a vacuum, compute the speed (in ...

*October 21, 2012 by andrew*

**physics**

A car is traveling at 25m/s when an accident occurs. The car decelerates 300m/s^2 but the passenger does not slow down because he is not wearing a seatbelt. a) Supposing the distance between the passenger and the dashboard is initially 0.50m, what will be the speed of the car ...

*February 10, 2013 by rob*

**Physic**

In a dramatic lecture demonstration, a physics professor blows hard across the top of a copper penny that is at rest on a level desk. By doing this at the right speed, he can get the penny to accelerate vertically, into the airstream, and then deflect it into a tray. Assuming ...

*May 7, 2011 by Chao*

**Physics**

A 0.38-kg particle has a speed of 2.0 m/s at point A and kinetic energy of 7.5 J at point B. (a) What is its kinetic energy at A? J (b) What is its speed at point B? m/s (c) What is the total work done on the particle as it moves from A to B?

*September 27, 2011 by Anonymous*

**Physics please clarify**

The potential at location A is 379 V. A positively charged particle is released there from rest and arrives at location B with a speed vB. The potential at location C is 789 V, and when released from rest from this spot, the particle arrives at B with twice the speed it ...

*September 1, 2007 by Mary*

**physics**

A pitcher claims he can throw a 0.146 kg baseball with as much momentum as a 3.37 g bullet moving with a speed of 15238 m/s. What must be its speed if the pitcher’s claim is valid? Answer in units of m/s What is the kinetic energy of the bullet? Answer in units of J What is ...

*January 30, 2012 by kesha*

**General Physics**

A 0.377 kg bead slides on a curved wire, starting from rest at point A(4.8 meters) as shown in the figure. The acceleration of gravity is 9.8 m/s2 . A. If the wire is frictionless, find the speed of the bead at B(0 Meters). Answer in units of m/s B. Find the speed of the bead ...

*July 26, 2013 by Charles*

**Physics**

A resting eagle on a tree top finds a rabbit on the ground at a distance of 50 m from the base of the tree. The eagle applies a constant horizontal speed and uses gravity to descend. It catches the rabbit in 2.5 seconds. a. What is the height of the tree top? b. What is the ...

*November 2, 2013 by Tsunayoshi*

**Physics**

An archer fires an arrow, which produces a muffled "thwok" sound after it hits a target. If the archer hears the "thwok" exactly 1.2 s after firing the arrow and the average speed of the arrow was 48 m/s, what was the distance separating the archer and the target? Use 340 m/ s...

*August 30, 2016 by Anonymous*

**algebra**

Andy’s average driving speed for a 4-hour trip was 45 miles per hour. During the first 3 hours he drove 40 miles per hour. What was his average speed for the last hour of his trip?

*April 24, 2013 by jj*

**physics**

Satellite A orbits a planet with a speed of 10,000 m/s. Satellite B is twice as massive as satellite A and orbits at twice the distance from the center of the planet. What is Satellite B's speed?

*October 2, 2008 by Jennifer*

**Math**

Pete and jan compete as a team in a biathlon. Pete runs at a speed of 9 km/ h for x hours. Jan cycles at twice Pete's running speed for 1 hour and 30 minutes. The total distance of the biathlon is 42 km. Find, in hour and minutes, Pete's running time.

*May 26, 2008 by Ephraim*

**Math**

two boats leave the same port at the same time. one travels at a speed of 29 mph in the direction N 50 degrees E and the other travels at a speed of 35 mph in the direction S 70 degrees E. how far apart are the two boats after an hour.

*October 28, 2015 by Claire*

**Word Problems**

I have two questions: Inflation is currently causing the cost of items to increase by about 2.5% per year. In 2009 a litre of gasoline costs approximately $0.90. What will it cost to fill a 60 litre gas tank 10 years from now? Round your answer to the nearest dollar. Name at ...

*January 12, 2011 by Hailey*

**Trig Circular Motion**

A es004-1.jpginch circular saw blade rotates at 5200 revolutions per minute. a) Find the angular speed of the saw blade in radians per minute. b) Find the linear speed in feet per minute of one of the 24 cutting teeth as they contact the wood being cut.

*March 31, 2012 by Emily*

**Physical Education**

Suppose that blood flows through the aorta with a speed of 0.35 m/s. The cross-sectional area of the aorta is 2.0x10-4 m2. (a) Find the volume flow rate of the blood (b) The aorta branches into tens of thousands of capillaries whose total cross-sectional area is about 0.28 m2...

*May 13, 2013 by Janaiby*

**physics**

quick answer of a boy is running on a straight road.He run towards north in 2 minutes and 10 seconds and then turn back and runs 200m in one minute.Calculate his average speed and magnitude of average velocity during first 2 minutes and 10 seconds and his average speed and ...

*June 22, 2010 by tarun*

**physics**

A baseball (m = 149 g) approaches a bat horizontally at a speed of 39.8 m/s (89.0 mph) and is hit straight back at a speed of 45.8 m/s (102 mph). If the ball is in contact with the bat for a time of 1.27 ms, what is the average force exerted on the ball by the bat? Neglect the...

*January 19, 2012 by Jen*

**algebra**

An airplane encountered a head wind during a flight between Rontown and Sawburgh which took 4 hours and 24 minutes. The return flight took 4 hours. If the distance from Rontown to Sawburgh is 1700 miles, find the airspeed of the plane (the speed of the plane in still air) and ...

*February 8, 2012 by jon*

**physics**

An 82.0 kg skydiver jumps out of a balloon at an altitude of 1 500 m and opens the parachute at an altitude of 195 m. (a) Assuming that the total retarding force on the diver is constant at 55.0 N with the parachute closed and constant at 3 600 N with the parachute open, what ...

*March 8, 2012 by Anonymous*

**Physics**

A wind turbine is initially spinning at a constant angular speed. As the wind's strength gradually increases, the turbine experiences a constant angular acceleration of 0.180 rad/s2. After making 2874 revolutions, its angular speed is 139 rad/s. A. What is the initial angular ...

*March 30, 2012 by Natasha*

**physics**

A wind turbine is initially spinning at a constant angular speed. As the wind's strength gradually increases, the turbine experiences a constant angular acceleration 0.170 rad/s2. After making 2870 revolutions, its angular speed is 131 rad/s. (a) What is the initial angular ...

*July 16, 2013 by kyle*

**physics**

If a car takes a banked curve at less than the ideal speed, friction is needed to keep it from sliding toward the inside of the curve (a real problem on icy mountain roads). (a) Calculate the ideal speed to take a 95 m radius curve banked at 15°. m/s (b) What is the minimum ...

*July 21, 2014 by Shonda*

**phy**

A wind turbine is initially spinning at a constant angular speed. As the wind's strength gradually increases, the turbine experiences a constant angular acceleration 0.130 rad/s2. After making 2844 revolutions, its angular speed is 136 rad/s. (a) What is the initial angular ...

*April 14, 2016 by ang*

**Physics**

As measured from centre ice, a single wildly cheering hockey fan can produce a sound intensity level of 60dB. What sound intensity level would be produced by 20 000 cheering fans? --------- If sound waves travel through the ground with an average speed of 6150 m/s and a ...

*May 15, 2012 by HelpMeWithPhysics*

**physics**

moving beltway at an airport has a speed v1 and a S length L. A woman stands on the beltway as it moves from one end to the other, while a man in a hurry to reach his flight walks on the beltway with a speed of v2 relative to the moving beltway. (a) What time inter- val is ...

*May 23, 2016 by anonymous*

**physics**

A man pushing a crate of mass m = 92.0 kg at a speed of v = 0.845 m/s encounters a rough horizontal surface of length scripted l = 0.65 m as in the figure below. If the coefficient of kinetic friction between the crate and rough surface is 0.357 and he exerts a constant ...

*June 3, 2013 by Melissa*

**physics 111**

A runner times his speed around a circular track with a circumference of 0.508 mi. At the start he is running toward the east and the track starts bending toward the north. If he goes halfway around, he will be running toward the west. He finds that he has run a distance of 0....

*September 14, 2007 by bob*

**college physics**

The electrons that produce the picture in a TV set are accelerated by a very large electric force as they pass through a small region in the neck of the picture tube. This region is 1.4 cm in length, and the electrons enter with a speed of 1× 105 m/s and leave with a speed of...

*September 16, 2008 by Ace*

**physics**

A train slows down at a constant rate as it rounds a sharp circular horizontal turn. Its initial speed is not known. It takes 19.8 s to slow down from 81 km/h to 37 km/h. The radius of the curve is 164 m. As the train goes around the turn, what is the magnitude of the ...

*June 16, 2011 by JRD*

**physics**

At a track-and-field meet, the best long jump is measured as 8.00 m. The jumper took off at an angle of 46° to the horizontal. (a) What was the jumper’s initial speed? (Neglect air resistance.) 1 m/s (b) If there were another meet on the Moon and the same jumper could ...

*October 20, 2011 by joe*

**physics**

A speeder traveling at a constant speed of 125km/h races past a billboard. A patrol car pursues from rest with constant acceleration of (8.0km/h)/s until it reaches its maximum speed of 190km/h, which it maintains until it catches up with the speeder. (a) How long does it take...

*August 27, 2013 by alex*

**PHYSICS(elena)**

Consider a rocket in space that ejects burned fuel at a speed of vex= 1.5 km/s with respect to the rocket. The rocket burns 8 % of its mass in 280 s (assume the burn rate is constant). (a) What is the speed v of the rocket after a burn time of 140.0 s? (suppose that the rocket...

*December 8, 2013 by Anonymous*

**Physics**

A batter hits a baseball so that it leaves the bat with initial speed of 40 m/s, at an angle of 60°. Tom Brady throws an incomplete pass at an initial speed of ~ 60 miles/hour (mph). When the ball was released, it’s initial velocity made an angle of ~45° with respect to ...

*February 1, 2015 by Anonymous*

**college**

A ceiling fan has 15 -inch blades (so the radius of the circular fan is 15 inches). Suppose the fan turns at a rate of 60 revolutions per minute. (a) Find the angular speed of the fan in radians per minute. (b) Find the linear speed of the tip of a blade in feet per second. Do...

*September 11, 2016 by Ange*

**algebra**

A man flies a small airplane from Fargo to Bismarck, North Dakota --- a distance of 180 miles. Because he is flying into a head wind, the trip takes him 2 hours. On the way back, the wind is still blowing at the same speed, so the return trip takes only 1 hours. What is the ...

*February 13, 2017 by marc*

**Physics ( Calculus & Mecahnics )**

A proton with mass m moves in one dimension.The potential-energy function is where and are positive constants. The proton is released from rest a x0 = a/b. (a) Show that can be written as U(x) = a --- [ ( x0/x )^2 - x0/x ] x0^2 Graph U(x). Calculate U(x0) and thereby locate ...

*January 23, 2011 by Clark*

**Alg**

A car with good tread can stop in less distance than a car with poor tread. A model for the stopping distance d, in feet, of a car with good tread on dry cement is d = 0.04v2 + 0.5v, where v is the speed of the car in miles per hour. If the driver must be able to stop within ...

*April 16, 2014 by K*

**physics**

A motorcycle stunt rider wants to do a loop-the-loop within a vertical circular track. If the radius of the circular track is 10.0 m, what minimum speed must the motorcyclist maintain to stay on the track? Suppose the radius of the track was doubled. By what factor will the ...

*April 11, 2012 by myra*

**Physics**

planet orbits a star once every 2.84 10^7 s in a nearly circular orbit of radius 1.42 10^11 m. (a) With respect to the star, determine the angular speed of the planet. (b) With respect to the star, determine the tangential speed of the planet. (c) With respect to the star, ...

*November 16, 2011 by Kelsey*

**physics**

5) After catching the ball, Sarah throws it back to Julie. The ball leaves Sarah's hand a distance 1.5 meters above the ground, and is moving with a speed of 22.0 m/s when it reaches a maximum height of 9.0 m above the ground. What is the speed of the ball when it leaves Sarah...

*September 10, 2012 by Jake*

**physics**

Given the information which statements are true or false? We know that when we pluck a string on an instrument the resulting sound wave travels through the air at a speed of (about) 344 m/s. But the wave moving on the STRING itself doesn't have to travel at 344 m/s. Let's ...

*March 31, 2011 by Student in Need*

**Physics**

You swing a 3.24-kg object in a vertical circle of radius 0.920 m. The speed of the object at the top of the circle is 3.25 m/s; the speed of the object at the bottom of the circle is 6.90 m/s. Find the tension in the rope tied to the object at: a) The top of the circle b) The...

*October 10, 2011 by John*

**physics**

At t = 0, an automobile traveling north begins to make a turn. It follows one-quarter of the arc of a circle of radius 9.3 m until, at t = 1.38 s, it is traveling east. The car does not alter its speed during the turn. (a) Find the car's speed. ___ m/s (b) Find the change in ...

*February 8, 2010 by Cindy*

**physics**

A 80 kg object slides at a 20 degree plane downward at 5m/s. An object 2 collides with object 1 by falling from 7 meter height and they stick together. Final speed of objects? I know the speeds would be the same. Would momentum equation work to solve this? The perfect ...

*October 25, 2012 by Laura*

**maths --plse help me..**

A man drives fom the origin to his destination in his car at the speed of 24km/hr and reaches 5 minutes late.Next day he drives from the same origin to the same destination with a speed of 30km/hr and reaches 4 minutes early.Find at what distance is the origin from the ...

*December 11, 2012 by angad*

**Precalculus**

Rosea drives her car 30 kilometers to the train station, where she boards a train to complete her trip. The total trip is 120 kilometers. The average speed of the train is 20 kilometers per hour faster than that of the car. At what speed must she drive her car if the total ...

*March 11, 2010 by Alonzo*

**Grade 11 Physics**

Megan and Catrina are at a playground swing set. Catrina pulls Megan back so that the 2.5 m long chain makes a 35 angle with the vertical. She pushes her with a speed of 6.5 m/s and Megan begins to swing forward. a) What is Megan’s fastest speed? b) How fast is Megan ...

*November 16, 2016 by Alexis*

**Physics/Math**

A thin rod, of length L and negligible mass, that can pivot about one end to rotate in a vertical circle. A heavy ball of mass m is attached to the other end. The rod is pulled aside through an angle and released. (a)What is the speed of the ball at the lowest point if L = 2....

*March 7, 2007 by Technoboi11*

**Physics**

Two blocks are connected by a light string that passes over a frictionless pulley as in the figure below. The system is released from rest while m2 is on the floor and m1 is a distance h above the floor. (a) Assuming m1 > m2, find an expression for the speed of m1 just as ...

*March 19, 2012 by Lilly*

**Physics Homework Help**

1.) Auston’s racecar has a speed of 80 m/s when Auston releases a drag parachute. If the parachute causes a deceleration of -4 m/s2, how far will the car travel before it stops? 2.) Jordan throws a golfball straight up from the top of a building 50 meters high. The initial ...

*October 10, 2014 by Tori*

**Math**

Light travels at a speed of about 186,000 miles per second. Sound travels at a speed of about 1,087 feet per second. How many times faster light travels than sound.

*November 3, 2010 by Rose*

**winterWx**

Compute the rms speed of a nitrogen molecule at 31.0°C. At what temperature will the rms speed be half that value? At what temperature will the rms speed be twice that value? T = 31 C = 304 K Mass M = 28 g/(6.02*10^23) = 4.65*10^-23 g = 4.65*10^-26 kg The average kinetic ...

*February 23, 2007 by Physics/Math*

**Math**

The quarterback of a football team releases a pass at a heights of 7 feet above the playing field, and the football is caught at a height of 4 feet, 30 yards directly downfield. The pass is released at an angle of 35 degrees with the horizontal. The parametric equations for ...

*April 21, 2014 by Brittany*

**physics**

If a car takes a banked curve at less than the ideal speed, friction is needed to keep it from sliding toward the inside of the curve (a real problem on icy mountain roads). (a) Calculate the ideal speed to take a 105-m radius curve banked at 13.0°. km/h (b) What is the ...

*November 30, 2012 by HELP!!!*

**Physics**

A 22kg child on a 1.75m long swing is released from rest when the swing supports make an angle of 35 degrees with the vertical. 1.What is the child's maximum potential energy? 2.Disregarding friction, find the child's theoretical speed at the lowest point. 3.If the actual ...

*December 13, 2015 by Carter*

**Pre-Algabra**

Unfortunately for mariners, the total amount of wave energy in a storm doesnt depend on the first power of wind speed, but on the fourth power. The seas generated by forty knot wind arent twice as violent as those from a twenty knot wind, they are 17 times more violent. A ...

*February 8, 2008 by Mackenzie*

**Physics**

A 44.0 kg man stands on a bathroom scale in an elevator. Starting from rest, the elevator ascends, attaining its maximum speed of 1.90 m/s in 1.19 s. It travels with this constant speed in the upward direction for the next 7.60 s. The elevator then slows down (undergoes a ...

*September 9, 2011 by Elisabeth*

**Physics**

From the top of a tower is an object with mass 25 kg which is lowered with ropes at a constant speed, 4 m / s to the ground. After 10 seconds the rope by which an object falls freely. From the moment there are 12 seconds to those standing on top of the tower hears the sound of...

*October 19, 2010 by Oddbjørn*

**Physics**

A person standing close to a railroad crossing hears the whistle of an approaching train. He notes that the pitch of the whistle drops as the train passes by and moves away from the crossing. The frequency of the distant approaching whistle is 540 Hz; it drops to 470 Hz after ...

*December 7, 2012 by Emily*

**Physics**

Compare the maximum speeds at which a car can safely navigate a flat, unbanked turn of radius 50.0 m in dry conditions versus snowy conditions. The coefficient of static friction in dry weather is 0.90, and in snowy weather it is 0.10. So, find the maximum speed for each ...

*November 15, 2015 by Smit*

**Physics**

Two stunt drivers drive directly toward each other. At time t=0 the two cars are a distance D apart, car 1 is at rest, and car 2 is moving to the left with speed v_0. Car 1 begins to move at t=0, speeding up with a constant acceleration a_x. Car 2 continues to move with a ...

*May 26, 2009 by RJ*

**physics**

A playground carousel (“merry-go-round”) is free to rotate frictionlessly in the horizontal plane (and air resistance is negligible). Without riders, the carousel has a moment of inertia of 152 kg·m2. But there is a single rider, initially standing 1.85 m from the axis of...

*November 1, 2010 by becca*

**Classical Mechanics**

Mary wants to throw a can straight up into the air and then hit it with a second can. She wants the collision to occur at height h=5.0 m above the throw point. In addition, she knows that she needs t1=4.0 s between successive throws. Assuming that she throws both cans with the...

*September 18, 2013 by Anon*

**Physics**

James and Steve have a contest to see who can kick a football further. James kicks the football at an angle up of 57 degrees, and a speed of 75m/s. Steve kicks the ball with a speed of 100m/s, at an angle up of 48 degrees? Who wins the contest?

*June 21, 2011 by Anonymous*

**physics**

A heavy wooden block rests on a flat table and a high-speed bullet is fired horizontally into the block, the bullet stopping in it. How far will the block slide before coming to a stop? The mass of the bullet is 10.5 g, the mass of the block is 10.5 kg the bullet’s impact ...

*March 10, 2010 by Anonymous*

**physics**

A heavy wooden block rests on a flat table and a high-speed bullet is fired horizontally into the block, the bullet stopping in it. How far will the block slide before coming to a stop? The mass of the bullet is 10.5 g, the mass of the block is 10.5 kg the bullet’s impact ...

*March 10, 2010 by esther*

**physicS IMP PLS**

Consider a rocket in space that ejects burned fuel at a speed of Vex = 1.5 km/s with respect to the rocket. The rocket burns 5% of its mass in 280 seconds. (a) What is the speed V of the rocket after a burn time of 140 seconds (in m/s)? (b) What is the instantaneous ...

*December 9, 2013 by Hil*

**Physics**

A. Consider the motion of a projectile. It is fired at t= 0. Its initial speed is 12 m/s and its initial projection angle is 50◦ from the horizontal. The acceleration of gravity is 9.8 m/s^2. What is the maximum height,h, of its trajectory? Answer in units of m. B. ...

*February 19, 2014 by Fabricus*

**physics**

In a simple model of the wind speed associated with hurricane Emily, we assume there is calm eye 10.0 km in radius. The winds, which extend to a height of 5550 m, begin with a speed of 208.0 km/hr at the eye wall and decrease linearly with radial distance down to 0 km/hr at a ...

*March 19, 2008 by shelby*

**Physics doppler effect**

A radar device emits microwaves with a frequency of 4.73E+9 Hz. When the waves are reflected from a van moving directly away from the emitter, the beat frequency between the source wave and the reflected wave is 751 beats per second. What is the speed of the van? (Note: ...

*May 16, 2011 by Joan*

**Physics**

Amotorvehicle of mass 1200kg is travelling along alevel road at 54km/hr.The breaks are then applied and the speed of the vehicle reduced to 18km/hr over adistance of 50M .if the afriction motion resistant is constant at 160N .calculate the effective braking force of the brakes...

*March 24, 2016 by John*

**chem 101**

. In an electron microscope the electrons generate the image. For one of the scanning electron microscopes in our Central Analytical Facility, the electrons are accelerated to have a kinetic energy of 200,000 eV. Electrons with this kinetic energy have a velocity of 2.67 x 10^...

*April 13, 2012 by Anonymous*

**PHYSICS IMP PLS**

Consider a rocket in space that ejects burned fuel at a speed of v_ex= 2.0 km/s with respect to the rocket. The rocket burns 10 % of its mass in 290 s (assume the burn rate is constant). (a) What is the speed of the rocket after a burn time of 145.0 s? (suppose that the rocket...

*December 8, 2013 by ROMA*

**projectile motion physics**

Imagine the ball on the left is given a nonzero initial speed in the horizontal direction, while the ball on the right continues to fall with zero initial velocity. What horizontal speed vx must the ball on the left start with so that it hits the ground at the same position as...

*March 8, 2015 by Kevin*

**Physics**

In the sport of skeleton a participant jumps onto a sled (known as a skeleton) and proceeds to slide down an icy track, belly down and head first. In the 2010 Winter Olympics, the track had sixteen turns and dropped 126 m in elevation from top to bottom. (a) In the absence of ...

*February 26, 2013 by Bonny*

**Physics**

In the sport of skeleton a participant jumps onto a sled (known as a skeleton) and proceeds to slide down an icy track, belly down and head first. In the 2010 Winter Olympics, the track had sixteen turns and dropped 126 m in elevation from top to bottom. (a) In the absence of ...

*February 26, 2013 by Bonny*

**Physics**

The potential at location A is 379 V. A positively charged particle is released there from rest and arrives at location B with a speed vB. The potential at location C is 789 V, and when released from rest from this spot, the particle arrives at B with twice the speed it ...

*September 2, 2007 by Mary*