Question

frictiion ch 5..........

Answer 1

AnSwEr :-
b) It is easier to push lighter box because it's weight is less so the frictional force which oppose it also be less and that's why it is easier to push lighter box than heavier box.
c) Yeah force needs to start a cart is greater than the force keep to maintain in its uniform motion as in rest frictional force is more than in motion.
d) They (Sportsman) uses shoe fitted with spikes so they increase their friction as it helps them to make a good grip so they run fast.