 # Work And energy Worksheet

Given below are the Class 9 Science Work And energy Worksheet
a. Concepts questions
b. Calculation problems
c. Multiple choice questions
e. Fill in the blank's

Question 1.
What do you understand by transformation of energy? Explain with the help of suitable example?

Question 2.
List two essential conditions for work to be done?

Question 3.
Define energy?

Question 4.
Define work? Write an expression of work in terms of force and displacement. State SI unit of work done?

Question 5.
Compare the kinetic energies of two objects of masses 10kg anf 50kg respectively but having same momentum?

Question 6.
What is a work done on a body moving in a circular path?

Question 7.
Identify the state the type of energy transformation in the following cases:
a.Riding a bicycle
b.Burning of cracker

Question 8.
Define potential energy? Write an expression for potential energy. Write the SI unit of potential energy?

Question 9.
What is work done by the force of gravity on a satellite moving round the earth? Justify the answer?

Question 10.
Define kinetic energy? Write an expression for kinetic energy? Write the SI unit of kinetic energy?

Question 11.
Define 1 Watt of power? A lamp consumes 1000J of electrical energy in 10s. Calculate its power?

Question 12.
Name the two types of mechanical energy? Give two examples when an object possesses both types of energies?

Question 13.
Calculate the amount of work required to stop a car of 1000kg moving with a speed of 72km/h?

Question 14.
Does the gravitational potential energy of a body depend on the path along which the body is moved, while going from one point to another? Illustrate your answer with the help of suitable example?

Question 15.
An object thrown at a certain angle to the ground moves in a curved path and falls back to the ground. The initial and the final points of the path of the object lie on the same horizontal line? What is the work done by the force of gravity on the object?

Question 16.
State the kind of energy transformation that takes place in the following devices:
a. Solar battery
b.Electric motor
c.Microphone
d.Thermal power plant
e.Hydroelectric power plant

Question 17.
Can a body have energy without momentum? Explain?

Question 18.
Can a body have momentum without having energy? Explain?

Question 19.
Define potential energy? Give SI unit? State two factors on which the magnitude of potential energy depends. Give one example each for the change in potential energy due to:
a.position
b.configuration of the body?

Question 20.
Calculate the kinetic energy of a car of mass 750kg moving with a velocity of 54km/. Find the new kinetic energy of a car if passenger of mass 50kg sit in the car?

Question 21.
Establish a relationship between momentum and kinetic energy of a body?

Question 22.
Calculate the kinetic energy of a car of mass 500kg moving with a velocity of 18Km/h. Find the new kinetic energy if two passengers of mass 50 kg each sit in the car?

Question 23.
Derive an expression for the kinetic energy of an object?

Question 24.
A man whose mass is 50 kg climbs up 30 steps of a stair in 30 s. If each step is 20 cm high, calculate the power used in climbing the stairs. [Given g = 10 m/s2]