Question

A bullet of mass 10 g travelling horizontally with a velocity of 150 ms1 strikes a stationary wooden block and comes to rest in 0.03 s. Calculate the distance of penetration of the bullet into the block. Also calculate the magnitude of force by wooden block on the bullet.

Answer 1

Dear Student,

we know that

v = u + at

or deceleration

a = (v - u) / t

here,

u = 150 m/s

v = 0

t = 0.03 s

so,

a = (0 - 150) / 0.03

thus,

a = -5000 m/s²

now, the distance penetrated will be

s = (v² - u²) / 2a

or

s = (0 - 150²) / (2x-5000) = 22500 / 10000

thus,

s = 2.25m

..

the retarding force exerted will be

F = ma

here,

m = 10g = 0.01kg

so,

F = 0.01 x 5000

thus,

F = 50N

Regards