Question

a 2 kg block is dropped from a height of 10 m and loses 28% of its mechanical energy by the time it reaches the ground.with what speed does it hit the ground?

a 20 gram bullet is shot vertically upwards 200 m/s into an initially stationary 2kg block, after which they move together. how high do they travel?

Answer 1

1)

Given,

mass of the block= 2kg.

Height of the block= 10 m

The initial energy of the block in the form of potential energy and the final energy is in the form of kinetic energy.

Now according to question,

2).

Given, mass of the bullet,

mass of the block,

initial bullet velocity

after hitting the block, both move together,

Let final velociy of both,

applying conservation of momentum,

Now, Let's say they travel to a height, h

According to conservation of energy,