Question

A boy and his skateboard have a combined mass of 65 kg. What is the speed of the boy and skateboard if they have a momentum of 275 kg • ? 0 m/s 0.24 m/s 4.2 m/s 8.5 m/s

Answer 1

Answer : Speed is 4.2 m/s

Explanation :

The combined mass of the boy and the skateboard is 65 kg

The momentum of the boy and the skateboard is 275 kg m/s

The momentum is given by:

p = m v

where m is the combined mass of boy and the skateboard.

v is the speed of both boy and the skateboard.

$v=\dfrac{p}{m}$

$v=\dfrac{275\ kg\ m/s}{65\ kg}$

$v=4.23\ m/s$

The speed of the boy and the skateboard is 4.2 m/s

So, the correct option is (C).

Hence, this is the required solution.

Answer 2

4.2m/s. Momentum=mass x velocity so 275/65=velocity=4.23