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 ballistic demonstration, a police officer fires a bullet of mass 50g with a speed of 220m//s on a wooden target. The bullet emerges with 20% of its initial K.E. 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 has a mass of 20 g and is moving with a speed of 1000 cms^(-1) . It can penetrate 10 cm of a given target before coming to rest. If the same target were only 6 cm thick, what will be the speed of the bullet when it comes out ?

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

A bullet of mass 50g moving with a speed of 500 ms^(-1) is brought to rest in 0.01s Find the impulse and the average force .

A bullet of mass 100gm moving with a velocity of 100ms^(-1) just pierces through a plank of 100cm thick.If it is 50cm thick it emerges with a velocity