MEDIUM
9th CBSE
IMPORTANT
Earn 100

What is difference between potential energy and kinetic energy?

Important Questions on Work and Energy

MEDIUM
9th CBSE
IMPORTANT
Secondary Physics>Chapter 5 - Work and Energy>EXERCISES>Q 8
What do you understand by energy transformation? Explain some of its common uses.
MEDIUM
9th CBSE
IMPORTANT
Secondary Physics>Chapter 5 - Work and Energy>EXERCISES>Q 9

Find the expression for the gravitational potential energy of a body of mass m at a height h.

MEDIUM
9th CBSE
IMPORTANT
Secondary Physics>Chapter 5 - Work and Energy>EXERCISES>Q 10

A car of mass 1500 kg is at rest. What is the force (in newtons) required to accelerate the car from rest to a speed of 20 m/s? Distance covered by the car is 40 m.

(Only write the magnitude of the answer in the given box, no need to write the unit.)

EASY
9th CBSE
IMPORTANT
Secondary Physics>Chapter 5 - Work and Energy>EXERCISES>Q 11
The work done when a force of 6000 N moves a body through a distance of 9 m is X kJ. Find the value of X.
EASY
9th CBSE
IMPORTANT
Secondary Physics>Chapter 5 - Work and Energy>EXERCISES>Q 12
If 200 J of work was done when a force of 12.5 N acts, what was the distance moved by the force?
(Solution should contain only magnitude and it should be in terms of SI units.)
MEDIUM
9th CBSE
IMPORTANT
Secondary Physics>Chapter 5 - Work and Energy>EXERCISES>Q 13
A lift carries 5 persons with an average mass of 60 kg to a height of 27 m in 9 seconds at a constant speed. What is the power (in watt) of the lift? Take g=9.8 m s-2
(Solution should contain only magnitude of power).
EASY
9th CBSE
IMPORTANT
Secondary Physics>Chapter 5 - Work and Energy>EXERCISES>Q 14

A person lifts 80 kg suitcase from the ground and puts on his head 2 m above the ground. Calculate the work done by the person.

HARD
9th CBSE
IMPORTANT
Secondary Physics>Chapter 5 - Work and Energy>EXERCISES>Q 15
The power of heart which beats 72 times in a minute is 1.2 kW. Calculate the work done by the heart for each heartbeat (in joules).