Advertisements
Advertisements
प्रश्न
A body of 2 kg falls from rest. What will be its kinetic energy during the fall at the end of 2 s? (Assume g = 10 m/s2)
Advertisements
उत्तर
Mass of the body, (m) = 2 kg
Initial velocity of the ball, (u) = 0 m/s
Time, (t) = 2s
Acceleration due to gravity, (g) = 10 m/s2
Let the final velocity of the ball after 2 s be (v)
We know v = u + at
So, v = 0 + 10 (2) = 20 m/s
Now we can find the kinetic energy as:
Therefore,
`K.E = 1/2 (2)(20)^2 "J"`
= 400 J
So, the kinetic energy of the moving object is 400 J.
APPEARS IN
संबंधित प्रश्न
Write an expression for the kinetic energy of an object.
The kinetic energy of an object of mass m moving with a velocity of 5 m s−1 is 25 J. What will be its kinetic energy when its velocity is doubled? What will be its kinetic energy when its velocity is increased three times?
An object of mass, m is moving with a constant velocity, v. How much work should be done on the object in order to bring the object to rest?
Kinetic energy = 1/2 × mass × ............
State two factors on which the kinetic energy of a moving body depends.
A cyclist doubles his speed. How will his kinetic energy change: increase, decrease or remain same?
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)
Find out the form of energy possessed by the following thing.
Water falls
The kinetic energy of a body of mass 4 kg and momentum 6 Ns will be
Find the kinetic energy of a body of mass 5 kg moving with a uniform velocity of 10 m s-1.
