Advertisements
Advertisements
प्रश्न
A cannon ball of mass 500 g is fired with a speed of 15 m s-1. Find:
- its kinetic energy.
- its momentum.
उत्तर
(i) Mass of canon ball = 500g = 0.5 kg
Speed, v = 15m/s
Kinetic energy of ball = `1/2 xx "mass" xx ("velocity")^2`
`= 1/2 ×0.5 ×(15)^2`
`= 1/2 ×0.5 ×225`
`=56.25 "J"`
(ii) Momentum of ball p = mv = `1/2 xx 15`
= 7.5 kg ms-1
APPEARS IN
संबंधित प्रश्न
Certain force acting on a 20 kg mass changes its velocity from 5 m s-1 to 2 m s-1. Calculate the work done by the force.
When a boy doubles his speed, his kinetic energy becomes
A body of mass 60 kg has the momentum 3000 kg m s-1. Calculate:
- the kinetic energy.
- the speed of the body.
A horse and a dog are running with the same speed. If the weight of the horse is ten times that of the dog, What is the ration of their kinetic energies?
When a ball is thrown inside a moving bus, does its kinetic energy depend on the speed of the bus? Explain.
If an object has 0 momentum, does it have kinetic energy? Explain your answer.
Explain the types of mechanical energy.
What is energy of motion? Give examples.
A body starts from rest and is acted on by a constant force. The ratio of kinetic energy gained by it in the first five seconds to that gained in the next five-second is:
A ball of mass 0.5 kg slows down from a speed of 10 m s-1 to that of 6 m s-1. Calculate the change in the kinetic energy of the ball.
