Question

A 10 gram bullet moving at 200 m per second stop after penetrating 5 cm of wooden plank the average force exerted on the plate will be

Answer 1

first find acc by formula v2-u2=2as
on calculation a= 4000m/s2
F=mxa mass=10/1000kg multiply by 4000
ans is 40N

Answer 2

"Here as we know :

Mass=10g=10/1000=0.01kg

Initial speed (u)=200m/s

Final velocity (v)= o m/s

S=5cm=5/100=0.05m

According to th eequation,V²-u²=2as

0²-(200)²=2ax0.05

-40000=ax5x2/100

-40000=a/10

a=-400000m/s²

According to the Newton's Second law: (The relationship between an object's mass m, its acceleration a, and the applied force F is F = ma.)

F=ma

=0.01x(-400000)

=-4000N

Thus, a A force of 4000N acts is exerted on the plate.