Quiz  /  Work Power and Energy Class 7 MCQ Questions With Answers

  • 1. 
    Check all of the things that can affect power

  • Work
  • Time
  • Force
  • All of above

  • 2. 
    When you rub your hands together on a cold day, you use friction to convert

  • Mechanical energy into thermal energy
  • Thermal energy into nuclear energy
  • Chemical energy into mechanical energy.
  • Electrical energy into thermal energy

  • 3. 
    A soccer player kicks a ball with 20 Newtons of force causing it to travel 100 meters. How much work is done on the ball?

  • 200 J
  • 80 J
  • 5 J
  • 2000 J

  • 4. 
    A weightlifter lifts two 300 newton weights 1.5 meters off the ground. How much work has she done?

  • 600 J
  • 450 J
  • 900 J
  • 1200 J

  • 5. 
    If 68 Joules were necessary to move a 4 Newton crate, how far was the crate moved?

  • 272 m
  • 17 m
  • 4.05 m
  • 272 cm

  • 6. 
    You move a 8 N object five meters in 4 seconds. How much power have you generated?

  • 160 watts
  • 10 watts
  • 6.4 watts
  • 17 watts

  • 7. 
    This picture shows an example of what type simple machine?

  • pulley
  • wedge
  • lever
  • wheel and axle

  • 8. 
    The sun provides ____________ and ____________ energy that can be harnessed and used for solar power.

  • chemical, sound
  • mechanical, light
  • sound, light
  • light, thermal

  • 9. 
    What type of energy do we use to cook food?

  • mechanical
  • radiant
  • thermal
  • kinetic

  • 10. 
    You do 90 joules of work in 30 seconds. How much power have you generated?

  • 30 watts
  • 3 watts
  • 120 watts
  • 270 watts

  • 11. 
    Which statement illustrates work done?

  • A weightlifter holds a barbell above her head.
  • A teacher applies a continuous force to a book, holding it flat.
  • A student flicks a paper football and moves it over the edge of a table.
  • A waiter carries a tray full of meals while listening to a customer.

  • 12. 
    How can you decrease the effort force needed to push a weight to the top of the ramp?

  • cover the surface with carpet
  • increase the length of the ramp
  • increase the height of the ramp
  • decrease the length of the ramp

  • 13. 
    At which point on the roller coaster is the kinetic energy at its maximum?

  • A
  • B
  • C
  • D

  • 14. 
    The amount by which a machine multiplies input force is known as the

  • work.
  • power.
  • output force.
  • mechanical advantage.

  • 15. 
    A student with a mass of 62 kg walks up a flight of stairs with a height of 3.4 meters. How can he decrease his power?

  • walk slower
  • walk faster
  • carry his friends books
  • All of above

  • 16. 
    A roller coaster whose average speed is 32 m/s is at the top of a 72m hill and weighs 966N. At the top of the hill the coaster car has ___________________ energy.

  • almost all kinetic energy
  • almost all potential energy
  • mostly kinetic energy
  • some kinetic and some potential energy

  • 17. 
    50 J of work is done lifting a 20.0 N book in the air. How high was it lifted?

  • 2.5 m
  • 3.5 m
  • 0.4 m
  • 25 m

  • 18. 
    Two workers use 100 N of force to move a sofa 2 meters in 2 seconds. How much power is required?

  • 100 watts
  • 400 watts
  • 104 watts
  • 50 watts

  • 19. 
    Simple machines make work easier by increasing what?

  • The distance over which work is done
  • The force needed to do work
  • The time required to do work
  • The acceleration of a massive object

  • 20. 
    This is energy that is stored for later use.

  • kinetic energy
  • potential energy
  • mechanical energy
  • radiant energy

  • 21. 
    What type of simple machine is a bike pedal?

  • Inclined Plane
  • Pulley
  • Wedge
  • Lever

  • 22. 
    Light is an example of _________

  • thermal energy
  • radiant energy
  • mechanical energy
  • nuclear energy
Report Question
warning
access_time
  Time