A gymnast of mass lands vertically on a thick foam mattress after completing a somersault
PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
A gymnast of mass 60kg lands vertically on a thick foam mattress after completing a somersault. The mattress allows her feet to remain in contact for a noticeably longer time than if she landed on a rigid floor.
(i) State Newton’s second law of motion in the form that relates force to the rate of change of momentum.
(ii) Using this form of the law, explain qualitatively why landing on the mattress reduces the force experienced by her legs compared with landing on a rigid floor.
(iii) If the total change in her linear momentum during landing is the same in both situations, show mathematically how the average force depends on the contact time.