Question

A bullet of mass 100g has attained a velocity of 1080 km h-1 towards the target what would be kinetic energy be at that moment

Answer 1

Answer:

Given,

Mass(M)=15gm =15×10

−3

kg

Initial velocity=400m/s

Distance travelled(s)=2cm=2×10

−2

m

(i) Kinetic energy=

2

1

mv

2

=

2

1

×15×10

−3

×(400)

2

=

2

1

×15×10

−3+4

×16

=1200J

(ii) The bullet strikes a thick target and is broght to rest in 2cm

work done=change in K.E

[v

f

=0 final velocity]

F.S=1200J−0

F=

2×10

−2

1200N

F=6×10

4

N

(iii) The Kinetic energy is converted to heat & sound energy.