Home
Class 12
PHYSICS
A bullet of mass 200 g hits a block of ...

A bullet of mass 200 g hits a block of thickness 6 cm with a speed of `100ms^(-1).` It emerges with `10%` of its initial KE. Find its emergent speed

Text Solution

Verified by Experts

Hint : `K_(l)=" initial KE"=(1)/(2)m u^(2)`
`m=(200)/(1000)kg`
`u=100ms^(-1)`
`"Final KE"=0.1 K_(l)=(1)/(2)mv^(2)`
`K_(i)="initial KE"=(1)/(2)m u^(2)=(1)/(2)xx(200)/(1000)xx100xx100=1000J`
`K_(f)="final KE "=0.1xxK_(i)=0.1 xx1000=100J`
`(1)/(2)mv^(2)=100`
`v=sqrt((2xx100)/((200)/(1000)))=10sqrt(10)=31.6ms^(-1)`
Speed is reduced by `68%` (not `90%`)
Promotional Banner

Similar Questions

Explore conceptually related problems

A bullet of mass 50 g enters a block of thickness t with speed of 500 ms^-1 . It emerges with 4% of its initial kinetic energy. The emergent speed is

In CID serial (on TV), Abhijeet fires a bullet of mass 100 g with a speed of 100ms^(-1) on a soft plywood of thickness 4 cm the bullet emerges with 10% of its initial KE. Find the emergent speed of the bullet.

In a ballistics demonstration, a police officer fires a bullet mass 50.0g with speed 200ms^(-1) on soft plywood of thickness 2.00cm. The bullet emerges only with 10% of its initial kinetic energy. What is the emergent speed of the bullet ?

In a ballistics demonstration, a police officer fires a bullet mass 50.0g with speed 200ms^(-1) on soft plywood of thickness 2.00cm. The bullet emerges only with 10% of its initial kinetic energy. What is the emergent speed of the bullet ?

In a ballistics demonstration, a police officer fires a bullet mass 50.0g with speed 200ms^(-1) on soft plywood of thickness 2.00cm. The bullet emerges only with 10% of its initial kinetic energy. What is the emergent speed of the bullet ?

A bullet of mass 20g enters into a fixed wooden block with a speed of 40 ms^(-1) and stops in it .Find the change in internal energy during the process

A bullet of mass 20 g has a n initial speed of 1ms^(-1) just before it starts penetrating a mud wall of thichness 20cm. If the wall offers a mean resistance of 2.5xx10^(-2)N the speed of the bullet after emerging from the other side of the wall is close to:

A bullet of mass 5 g travels with a speed of 500 ms^(-1) .if it penetrates a fixed target which offers a constant resistive force of 1000 N to the motion of the bullet ,find ,(a) the intial Kinetic energy of the bullet penetrated before coming to rest,and (c)the speed with which the bullet emerges out of the target if target is of thickness 0.5 m.

A bullet of mass 0.06 kg moving with a speed of 90ms^(-1) enters a heavy wooden block and it stopped after a distance of 60 cm. What is the average resistive force exerted by the block on the bullet ?

A bullet of mass 20 g has an initial speed of 1 ms^(-1) just before it starts penetrating a mud wall of thickness 20 cm. If the wall offers a mean resistance of 2.5 xx 10^(-2)N the speed of the bullet after emerging from the other side of the wall is close to: