A 60 kg man skating with a speed of 10 m/s collides with a 40 kg skater at rest and they cling to each other. Find the loss of kinetic energy during the collision.

Question

Philoid · Accepted Answer

Let the velocity of both the skaters after they cling to each other be ‘v’ m/s.

Total linear momentum of both the skaters before the collision = 60×10 + 40× 0

= 600 kg m/s

Then, total linear momentum of both skaters after the collision = v×(60+40)

= 100v kg m/s

Applying conservation of total linear momentum,

⇒ 100v = 600

⇒ v = 6 m/s

Total kinetic energy of both skaters before the collision

= 3000 + 0

= 3000 J

Total kinetic energy of both skaters after the collision

= 1800 J

Total loss in kinetic energy during this collision = 3000 – 1800

= 1200 J