Question

A bullet of mass 20 g travels with a speed of 800 m s-1

. If it penetrates

a fixed target which offers a constant resistive force of 2500 N to the

motion of the bullet, find:

a) Initial kinetic energy of the bullet.

b) Distance through which the bullet has penetrated before coming to

rest.

(c) If the target is of thickness 1.2 m what percentage of the kinetic

energy does the bullet still have compared to kinetic energy while

entering the target?
​

Answer 1

Answer:

a. ke init.= 1/2×20/1000×(800)^2

b. u is 800

v is 0

accn. is -2500×1000/20 (ms^-2)

so find the distance penetrated by using 3rd eqn ........

c. a us given

u is given

and also distance is given, so you find the final velocity of the bullet while exiting from that, and find final KE...

& %KE= final KE/initial KE ×100

(thanx bhej dena bhai badi mehnet kari hai......)