Advertisements
Advertisements
प्रश्न
How much work is needed to be done on a ball of mass 50 g to give it a momentum of 5 kg cm s-1?
Advertisements
उत्तर
Kinetic energy is related to momentum as
K.E. where K = `p^2/(2 m)` and p is the momentum of the body
K.E. is nothing but work done
∴ K.E. = Work done = `("momentum")^2/(2 xx "mass of body")`
= `(5)^2/(2 xx (50/1000))`
= `(5 xx 5)/(2 xx (1/20))`
Work done = `25/(1/10)`
= 25 × 10
= 250 J
APPEARS IN
संबंधित प्रश्न
Name the unit of physical quantity obtained by the formula `(2K)/v^2` Where K: kinetic energy, v: linear velocity
The energy of a flying kite is kinetic energy.
The kinetic energy of a body is the energy by virtue of its ______.
If the speed of a car is halved, how does its kinetic energy change?
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 truck weighing 1000 kgf changes its speed from 36 km h-1 to 72 km h-1 in 2 minutes. Calculate:
- the work done by the engine and
- its power (g = 10 m s-2)
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 car is accelerated on a levelled road and attains a speed of 4 times its initial speed. In this process, the kinetic energy of the car :
The kinetic energy of a body of mass 4 kg and momentum 6 Ns will be
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.
