While playing basketball in PE class, 67 kg Johan lost his balance after making a lay-up at 5.4 m/s and collided with the padded wall behind the basket and came to rest in 0.24 seconds. What force acted on his body?

As we know, that force can also be determined as the rate of change in momentum with respect to time from Newton’s second law of motion. In this case, we have to use this form of second law of motion.

So the initial parameters like initial speed/velocity at which Johan was playing is 5.4 m/s and then he will collide with padded wall and fall to ground making the final velocity as zero in a time of 0.24 seconds.

Also the mass of Johan is given as 67 kg. As, we know that momentum is the measure of product of mass with velocity of the body. So the force can be determined as

[tex]Force =\frac{\text { Change in momentum }}{\text { Time }}=\frac{(67 \times 0)-(67 \times 5.4)}{0.24}=\frac{-361.8}{0.24}=-1507.5 \mathrm{N}[/tex]

This is because, change in momentum = Final Momentum - Initial momentum

So, force = - 1507.5 N. The negative sign in the determined force magnitude indicates that the force acting on Johan will be reactional force with magnitude of 1507.5 N.