Worksheets5.2 Work Done and Conservation of Energy (PB)
Total questions: 10
Worksheet time: 15mins
Which expression gives the work done by a constant force acting through a displacement in the same direction?
W = F · v
W = F · d
W = F · t
W = F · a
A force of 50 N moves an object 3 m in the direction of the force. How much work is done?
150 J
50 J
300 J
15 J
Which statement about kinetic energy is correct?
It depends only on the object's mass.
It depends only on the object's velocity.
It depends on both mass and velocity squared.
It is independent of velocity.
The gravitational potential energy of an object of mass m at height h is given by which expression?
mgh
21 mgh^2
mg/h
mgh2
Which option best describes the principle of conservation of energy?
Energy can be created but not destroyed.
Energy can be destroyed but not created.
Energy cannot be created or destroyed, only transformed.
Energy is always lost in every process.
In an isolated system, the total energy:
Increases over time
Decreases over time
Remains constant
Depends on external forces
A 10 kg box is pushed up a smooth slope 5 m long at an angle of 30° to the horizontal. What is the work done against gravity? Take g = 9.8 m s⁻².
250 J
490 J
230 J
500 J
A 2 kg ball is dropped from a height of 3 m into sand, making an indent of 0.05 m. Assuming all potential energy is used to overcome the resistive force, what is the average resistive force? Take g = 9.8 m s⁻².
600 N
1200 N
300 N
900 N
A pellet of mass 25 g travelling horizontally at 40 m s⁻¹ enters a fixed wooden block and stops after travelling 2.5 cm in the block. What is the average resistive force acting on the pellet?
20 N
800 N
1600 N
8000 N
An object of mass m is accelerated from rest to a velocity v by a constant resultant force F. What is the work done on the object during this acceleration?
Fv/2
Fv
mv2
mv2/2
