A 4.0 kg circular disk slides in the x- direction on a frictionless horizontal surface

Solution :

Let kg

m/s

Let and are the speeds of the disk and  after the collision.

So applying conservation of momentum in the y-direction,

Therefore, the disk 2 have greater velocity and hence more kinetic energy after the collision.

Now applying conservation of momentum in the x-direction,

m/s

So,

          = 4.33 m/s

Therefore, speed of the disk 2 after collision is 4.33 m/s

Work done by the crane is 150,000 J

Explanation:

Given parameters are,

Force applied, F = 1000 N

Distance, d = 150 m

Hence, apply in the formula, W = 1000 X 150 = 150,000 J