There is a train A. On the roof of A is another frictionless train B of mass Mb. A mass Mc hangs off the front of A and is attached to the front of B by rope and frictionless pulley. How fast should A accelerate so that B wont fall off the roof of A.
You must carefully draw a diagram. The key to this question is to find from what perspective you should view it. The easiest way is to see that B wants to accelerate due to the weight of C. This is unaffected by the motion of A. We simply need to accelerate A at the same rate that B would accelerate so there will be no relative motion and so B wont fall off. We have the acceleration of b = (Mc*g)/(Mb+Mc) So that is what the acceleration of A should be.
SO
Related Physics A Level answers
All answers ▸How can I measure the orbital period of a satellite around Earth?
A rocket travels with constant velocity in a straight line in deep space. A ball is thrown from the back to the front (ie from the thrusters to the nose). Describe the path of the ball. Describe the path if the rocket were accelerating along this line.
A box is pulled with a rope at 26° to the horizontal and a tension of 120N. What is the work done in pulling it 5 metres?
Describe how the average density of matter in the universe affects its ultimate fate?