# Physics 30

posted by Mona

A system containing a frictionless pulley is described in the diagram on the right (the 2.0 kg box is on the floor while the 3.0 kg box is 0.5m high) . If this system is released, what will be the momentum of:

A. the 2.0 kg box when the 3.0 kg box hits the floor?

b. the 3.0 kg when it hits the floor?

1. bobpursley

a. I would work this by energy.
mass2 gains PE, and gains KE, the mass3 loses PE, and gainsKE. the net change in total energy is zero.
Both masses will have the same velocity.

1/2 2 V^2+2g*.5-3g*.5+1/2 3 v^2=0

v^2(1+3/2)=-g+1.5g
v= sqrt (.5g*2/3)=sqrt(g/3)

check that.

## Similar Questions

1. ### science: physics

A 2.0 kg breadbox on a frictionless incline of angle is connected, by a cord that runs over a pulley, to a light spring of spring constant , as shown in Fig. 8-42. The box is released from rest when the spring is unstretched. Assume …
2. ### Physics

(Apparently, I'm not allowed to post URLs, but this question is better illustrated by a diagram, i39. tinypic. com/ 17e336. jpg) <--P--[BOX A]<--Q--[BOX B]<--R--[BOX C] There are three boxes attached together with string and …

Mr. Mist’s ramp broke so he tried to lift the his 150 Newton box of ungraded papers with a pulley system. Mr. Mist had to pull the rope in his system 3 meters. The papers were lifted into his car by the pulley system which lifted …
4. ### physics

A 47 N box is pulled along a frictionless horizontal surface by a 25 N weight hanging from a cord on a frictionless pulley?
5. ### Physics

The diagram for this problem is a pulley. On the left end Box 1 is sitting on a table and Box 2 is attached sitting on top of Box 1 and is attached to the string for the pulley. The right side has the string attached to Box 3 which …
6. ### Physics 30

A system containing a frictionless pulley is described in the diagram on the right (the 2.0 kg box is on the floor while the 3.0 kg box is 0.5m high) . If this system is released, what will be the momentum of: A. the 2.0 kg box when …
7. ### Physics

Two boxes are connected by a light string that passes over a light, frictionless pulley. One box rests on a frictionless ramp that rises at 30° above the horizontal (see the Figure below), and the system is released from rest. (a) …
8. ### Physics 2

Two boxes are connected by a light string that passes over a light, frictionless pulley. One box rests on a frictionless ramp that rises at 30° above the horizontal (see the Figure below), and the system is released from rest. (a) …
9. ### physics

Two boxes are connected by a weightless cord running over a very light frictionless pulley as shown in the figure. Box A, of mass 8.0 kg, is initially at rest on the top of the table. The coefficient of kinetic friction between box …
10. ### physics

Two boxes are connected by a cord running over a pulley. Box A is on a table and Box B is hanging off of the pulley. The system is released from rest and Box B drops a distance D. What is the word done by gravity on box B?

More Similar Questions