# Kinetic Energy

## Trending Questions

**Q.**If the speed of an object is doubled then its kinetic energy

- is doubled
- becomes four times
- is tripled
- is halved

**Q.**

A ball of mass 2 kg and another of mass 4 kg are dropped together from a 60 feet tall building. After a fall of 30 feet, their respective kinetic energies will be in the ratio of

√2:1

1:2

1:2

1:√2

**Q.**

What do you mean by conservation of mechanical energy?State the condition when it holds.

**Q.**Two cylindrical vessel of equal cross sectional area A contain water up-to H1 and H2 the vessels are interconnected so that the levels in them become equal. Calculate the work done by the force of gravity during the process. The density of water is p(row)

**Q.**The kinetic energy of a moving cart

- gets doubled
- gets tripled
- remains same

**Q.**

How are kinetic energy and potential energy associated with the motion of any given object?

**Q.**

Kinetic energy of a body can be negative.

True

False

**Q.**

Define the momentum of a body.

**Q.**

How fast should a man weighing 600N needs to run, so that his kinetic energy is 750J? Take g=10ms−2

3ms−1

4ms−1

5ms−1

6ms−1

**Q.**

Pick the odd one out. Give a scientific reason for your answer.

Kinetic energy

mass of the object

speed of the object

gravitational force

**Q.**The kinetic energy is mathematically expressed as, K.E=12mv2

- False
- True

**Q.**

Statement 1: Force acting on a body increases its kinetic energy from 200 J to 400 J and the force does a positive work on the body.

Statement 2: A force does a positive work on an object when the displacement due to the force is in the direction of the force itself.

Both the statements are true and statement 2 is the correct explanation of statement 1.

Both the statements are true and statement 2 is not the correct explanation of statement 1.

Statement 1 is true but statement 2 is false.

Statement 1 is false but statement 2 is true.

**Q.**

What are the different types of energy?

**Q.**

A swinging pendulum has which type of energy?

20m height

10m height

When object touched the ground floor

Just before touching the ground floor

**Q.**

A child moving down a slide has which form of energy?

Kinetic energy

Potential energy

Electrical energy

None of these

**Q.**

Name and explain the various types of energies.

**Q.**

In a freely falling body, the interchange of potential to kinetic energy takes place _______.

alternately between kinetic and potential

similar to a pendulum

gradually from kinetic to potential

gradually from potential to kinetic

**Q.**

The value of potential energy at mean position of a swinging pendulum is _________.

**Q.**Define kinetic energy. Write the equation for kinetic energy. Two bodies of equal masses move with uniform velocities v and 3v respectively. Find the ratio of their kinetic energies. [5 MARKS]

**Q.**

What type of energy is associated with the motion of an object?

**Q.**

An iron sphere of mass of 10 kg has the same diameter as an aluminum sphere of mass is 3.5 kg. Both spheres are dropped simultaneously from a tower. When they are 10 m above the ground, they have the same

acceleration

momenta

potential energy

kinetic energy

**Q.**

A bike of mass $100kg$ and a car of mass $500kg$ are moving at the same speed. Find the ratio of their kinetic energies.

**Q.**A stone is held in the rubber of a catapult, the catapult is pulled and released in a horizontal direction. In this case energy transformation takes place from __________ energy to ___________ energy.

- potential, kinetic
- kinetic, heat
- kinetic, potential
- potential, heat

**Q.**

A bullet fired from a gun has a mass 100 g and velocity 1000 km/hr. What is its kinetic energy?

Choose the nearset value.

3864 J

4240 J

2586 J

6580 J

**Q.**

When a spring is compressed, 'A' amount of work is done on the spring, what was the value of its potential energy?

50 J

100 J

150 J

200 J

**Q.**

Two children are moving on two skateboards at the same speed, child A has a mass of 20 kg whereas child B has 30 kg mass. Which child has higher kinetic energy?

Child B

Both have the same kinetic energy

Both have potential energy.

Child A

**Q.**

What happens to kinetic energy when the work on the car of mass 1000kg increases its velocity from 10km/hr to 20km/hr?

12596 J

10590 J

11592 J

13542 J

**Q.**

1 Kwh = 36 ×

10

^{3}10

^{2}10

^{4}10

^{5}

**Q.**Two boxes of the same mass move with speeds v1 and v2 ( v1 > v2 ). Which box has greater kinetic energy?

- Box 1
- Box 2
- Both have equal energy
- Insufficient information

**Q.**A man going up has potential energy and kinetic energy both.

- False
- True