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.
Advertisements
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
When a boy doubles his speed, his kinetic energy becomes
A bullet of mass 50 g is moving with a velocity of 500 m s−1. It penetrated 10 cm into a still target and comes to rest. Calculate:
- the kinetic energy possessed by the bullet, and
- the average retarding force offered by the target.
A body of mass 10 kg is moving with a velocity 20 m s-1. If the mass of the body is doubled and its velocity is halved, find:
- the initial kinetic energy, and
- the final kinetic energy.
How does the kinetic energy of a moving body depend on its (i) speed, and (ii) mass?
On a level road, a scooterist applies brakes to slow down from a speed of 10 m/s to 5 m/s. If the mass of the scooterist and the scooter be 150 kg, calculate the work done by the brakes. (Neglect air resistance and friction)
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?
If an object has 0 momentum, does it have kinetic energy? Explain your answer.
The kinetic energy of a body of mass 4 kg and momentum 6 Ns will be
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:
Find the kinetic energy of a body of mass 5 kg moving with a uniform velocity of 10 m s-1.
