The diagram shows two blocks P and Q of masses 2 kg and 3 kg respectively connected by a light string passing over a smooth pulley. Block P starts from rest and moves through a distance of 5m on the smooth inclined plane while Q moves downwards. Take the acceleration due to gravity to be 10N/kg. What is the loss of gravitational potential energy of Q and gain in gravitational potential energy of P?
I worked ou the P.E of block P by the formula Ep=mgh. I got 60 J. But I don't know how to work for block Q?
Ok. If you are going by the energy method, then how much would the block Q move down??
by 2 meters
Nope
Would it move down by 5 metres?
Yes
how how come if the masses are differnt
See, the string is moving 5 m when the block P is moving up along the slope. Therefore, the same length of string would also move down for block Q
Ok. So the loss in P.E would be 150J?
Yes
Thank you!
Welcome
Join our real-time social learning platform and learn together with your friends!