Question

68.Two skateboarders push off from each other as we did in lecture. One has a mass of 80 kg, and the other has a mass of 72 kg.

The skateboarders exchange equal but opposite amounts of ∆v velocity.

True

False

69. Two skateboarders push off from each other as we did in lecture. One has a mass of 80 kg, and the other has a mass of 72 kg.

The skateboarders exchange equal but opposite amounts of ∆p momentum.

True

False

Answer 1

Linear momentum=mass *velocity.

Now,according to law of conservation of momentum,linear momentum of a system is conserved if no net external force acts on it.

So,when the 2 skateboarders collide, they exchange equal but opposite momentum, so that the net linear momentum of the system is conserved.

Now, note that the masses of the skateboarders are different.Since,they exchange equal momentum,they cannot exchange equal amounts of velocity as their masses are different.

Hence,the answers are:

68. False

69.True