Forces in collisions

Question 1

what is the law of conservation of momentum?

Answer 1

the total momentum before an event is equal to the total momentum after an event when the system is closed

Question 2

what is force equal to?

Answer 2

force is equal to the rate of change of momentum

Question 3

why is rubber foam a better material for playground floors than concrete?

Answer 3

-rubber is more flexible than concrete
-this makes the impact time longer
-this makes the rate of change of momentum smaller
-decreases the force
-this will protect the childs skull

Question 4

why is it advisable to bend your knees when parachuting?

Answer 4

-when a person bends their knees it makes them more flexible
-this makes the impact time longer
-this makes the rate of change of momentum smaller
-decreases the force
-this will protect the person from breaking their legs