Advertisements
Advertisements
प्रश्न
If an object has 0 momentum, does it have kinetic energy? Explain your answer.
Advertisements
उत्तर
Momentum of an object, P = mv
If P = 0
⇒ `"v" = 0`
This is because the mass of the object can never be 0.
Now, the kinetic energy of the object, `"K" = 1/2 xx "m" xx "v"^2`
Since, v = 0
⇒ K = 0
Hence, when the object has zero momentum, its kinetic energy is also zero.
APPEARS IN
संबंधित प्रश्न
Write an expression for the kinetic energy of an object.
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.
State two factors on which the kinetic energy of a moving body depends.
Two toy-cars A and Bof masses 200 g and 500 g respectively are moving with the same speed. Which of the two has greater kinetic energy?
A cyclist doubles his speed. How will his kinetic energy change: increase, decrease or remain same?
The kinetic energy of a body is the energy by virtue of its ______.
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)
A body of mass 60 kg has the momentum 3000 kg m s-1. Calculate:
- the kinetic energy.
- the speed of the body.
A body is thrown vertically upwards. Its velocity keeps on decreasing. What happens to its kinetic energy as its velocity becomes zero?
If the speed of a body is halved, what will be the change in its kinetic energy?
A man drops a 10 kg rock from the top of a 5 m ladder. What is its speed just before it hits the ground? What is its kinetic energy when it reaches the ground? (g = 10 m/s2)
Find out the form of energy possessed by the following thing.
Water falls
An apple falling from a tree is an example for kinetic energy.
What are the uses of mechanical energy?
Water stored in water dams possesses kinetic energy.
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:
When a bell fixed on a cycle rings, then the energy conversion that takes place is ______.
