K.C.S.E Physics Q & A - MODEL 2011PP1QN18

K.C.S.E Physics Q & A - MODEL 2011PP1QN18

(a) Figure 15 shows a metal bolt which is threaded.​

Explain how a metre rule can be used to measure the pitch (distance between adjacent peaks) of the threading. 
(b) Figure 16 shows a screw jack whose screw has a pitch of 1mm, and has a handle of 25 cm long.

Determine the velocity ratio of the jack. 
(c) A bullet of mass 60g travelling at 800m/s hits a tree and penetrates a depth of 15 cm before coming to rest.
(i) Explain how the energy of the bullet changes as it penetrates the tree. 
(ii) determine the average retarding force on the bullet.

answers