# Physics

A blue billiard ball with mass m crashes into a red billiard ball with the same mass that is at rest. The collision results in the blue billiard ball travelling with a velocity of v and the red billiard ball with a velocity of 3V. In terms of v and m determine the blue billiard ball's velocity before the collision.

1. Let the man run to point P, which is x meters upstream from the line AB. He swims across, being swept y meters downstream, and then runs to B.

We know that he is in the water for d/(v/3) = 3d/v seconds, so
y = 3d/v * v = 3d.

His path is thus

√(d^2+x^2) meters on land,
d meters in the water,
√((2d)^2+(x-3d)^2) meters on land to B

Now, dividing distance by speed, his time to travel is

t = 1/(3v) (√(d^2+x^2)+√((2d)^2+(x-3d)^2)) + 3d/v
=
√(d^2+x^2)+√(x^2-6dx+13d^2)+9d
--------------------------------------
3v

posted by Steve
2. Let the man run to point P, which is x meters upstream from the line AB. He swims across, being swept y meters downstream, and then runs to B.

We know that he is in the water for d/(v/3) = 3d/v seconds, so
y = 3d/v * v = 3d.

His path is thus

√(d^2+x^2) meters on land,
d meters in the water,
√((2d)^2+(x-3d)^2) meters on land to B

Now, dividing distance by speed, his time to travel is

t = 1/(3v) (√(d^2+x^2)+√((2d)^2+(x-3d)^2)) + 3d/v
=
√(d^2+x^2)+√(x^2-6dx+13d^2)+9d
---------------------------------------------
3v

posted by Steve

First Name

## Similar Questions

1. ### Physics

1. A stationary curling stone is struck in a glancing collision by a second curling stone of equal mass. If the first stone moves away at a velocity of 0.92 m/s [N71oW] and the second stone moves away at a velocity of 1.25 m/s
2. ### chemistry

The kinetic energy of a rolling billiard ball is given by {\rm{KE}} = 1/2\,mv^2 . Suppose a 0.17-{\rm kg} billiard ball is rolling down a pool table with an initial speed of 4.5 m/s. As it travels, it loses some of its energy as
3. ### Physics

Please help me. I need physics help. I don't understand how to do these questions. Can someone show me what I should use? and explain. I'll do calculations by myself. A stationary curling stone is struck in a glancing collision by
4. ### Physics

I need physics help. I don't understand how to do these questions. Can someone show me what I should use? and explain. I'll do calculations by myself. A stationary curling stone is struck in a glancing collision by a second
5. ### Chemistry/Physics

The kinetic energy of a rolling billiard ball is given by KE=1/2mv2. Suppose a 0.17-kg billiard ball is rolling down a pool table with an initial speed of 4.7m/s . As it travels, it loses some of its energy as heat. The ball slows
6. ### Physics help

Did i do number 2 and 3 correct? 2. A billiard ball (0.62 kg) with a velocity of 2.0 m/s [N] hits another ball and has a velocity of 1.7 m/s [E] after the collision. Determine the impulse on the ball and the average force exerted
7. ### Physics

A billiard ball traveling at 3.00 m/s collides perfectly elastically with an identical billiard ball initially at rest on the level table. The initially moving billiard ball deflects 30.0° from its original direction. What is the
8. ### chemistry

The kinetic energy of a rolling billiard ball is given by KE=1/2mv2. Suppose a 0.17-kg billiard ball is rolling down a pool table with an initial speed of 4.7m/s . As it travels, it loses some of its energy as heat. The ball slows
9. ### Physics

I'm preparing for a test. Can anyone check my answer for all these questions? These are my questions: 1. A stationary curling stone is struck in a glancing collision by a second curling stone of equal mass. If the first stone
10. ### Physics

I'm preparing for a test. Can anyone check my answer for all these questions? These are my questions: 1. A stationary curling stone is struck in a glancing collision by a second curling stone of equal mass. If the first stone

More Similar Questions