Question

a hammer of tje mass 1kg strikes on the head of a nail with a velocity of 2m/s .it drives the nail 0.01m into a wooden block. Find the force applied by the hammer and the time of impact.

Answer 1

mass m= 1kg
initial velocity u=2m/s
distance covered s=0.01m

so applying equation of motion
V²=U²+2as
here v=0
a=4/(2*0.01)
=200m/s²

so Force F=ma
m is mass and a is acceleration
F=1*200=200N

V=u+at
So time of impact t is
0=2+200t
t=2/200=0.01s or 1 milisecond

Answer 2

mass of hammer, M = 1kg
initial velocity, u = 2m/s
final velocity, v = 0
distance covered, s=0.01m

v² - u² = 2as
⇒ 0 - 2² = 2*a*0.01
⇒ -4 = 0.02a
⇒ a = -4/0.02 = -200 m/s²

time = (v-u)/a = (0-2)/(-200) = 0.01 second
Force = ma = 1*200 = 200N