Question

A 5 gm bullet is fired at a fixed target with a speed of 500 m/s , During penetration the target offered a resistance of 1000 N to the bullet, calculate kinetic energy of the bullet?​

Answer 1

Given,

mass=5g

speed=500m/s

force=1000N

(a) kinetic energy=

2

1

×m×v×v

m=5g=

1000

5

kg

v=500

⇒

2

1

×

1000

5

×500×500

=625J

(b) force=mass×acceleration

1000=

1000

5

×acceleration

Acceleration=1000×

5

1000

=200000m/s

2

using the third equation of motion

v

2

=u

2

+2as

(500)

2

=0+2×200000×s

250000=400000×s

s=0.625m