Worksheets05c - Work and Power
Total questions: 25
Worksheet time: 20mins
What is the unit of power?
newton
watt
meter
joule
Power is defined as __________.
force times distance
force divided by time.
work divided by time.
work times time.
If you exert a force of 10.0 N to lift a box a distance of 3 m, how much work do you do?
30J
300 J
90 J
900 J
A force acting on an object does no work if
a machine is used to move the object.
the force does not cause the object to move.
the force is greater than the force of friction.
the object accelerates.
Which of the following statements is true according to the law of conservation of energy?
Energy cannot be created.
Energy cannot be destroyed.
Energy can be converted from one form to another.
all of these
All statements below are correct about work, EXCEPT
It is a scalar quantity.
Its SI units is J (joule).
Work = Fd sinθ
Work = Fd cosθ
The K.E. of a particle is increased by a factor of 4. By what factor does its speed increase?
2
4
8
16
Refer to the diagram, what is the work done to load a barrel of mass 50 kg onto a lorry?
80 J
170 J
780 J
1700 J
Which of the following statements are true about kinetic energy?
None of these
Kinetic energy is the form of mechanical energy which depends upon the position of an object.
If an object is at rest, then it does not have any kinetic energy.
If an object is on the ground, then it does not have any kinetic energy.
At which point is potential energy greatest?
W
X
Y
Z
What type of energy is stored in food and fuel?
Chemical
Thermal
Potential
Calories
Ball A = 500kg B = 100kg
Bobby lifts a book to the second floor in 20 seconds. Carol lifts the same book to the second floor in 10 seconds. Who did more work?
Bobby
Carol
They did the same amount of work
Not enough information
If you hold a 20 N object 2 m off of the ground, how much work have you done?
40 J of Work
10 J of Work
No Work
18 J of Work
What is the kinetic energy of a 4 kg rock falling through the air at 5 m/s?
10 J
50 J
20 J
200 J
