Which of the following is true for the work-energy theorem?
Did this page help you?
Select a download format for Work-Energy Theorem
Which of the following is true for the work-energy theorem?
Choose your answer
Did this page help you?
A soccer player kicks a soccer ball at rest on the penalty spot. The player's kick exerts a force of 43 N on the ball in the direction of travel. The ball has 862 J of kinetic energy just before the goalkeeper catches it. Which of the following is the net work done on the ball?
Choose your answer
Did this page help you?
An object is dropped 120 m through a vacuum chamber.
Which of the following is the object's speed just before it hits the floor?
20 m/s
30 m/s
40 m/s
50 m/s
Choose your answer
Did this page help you?
A 5 kg cart is pushed with a force of 20 N over a distance of 4 m. If the cart was initially at rest, which of the following is the final kinetic energy of the cart?
10 J
20 J
40 J
80 J
Choose your answer
Did this page help you?
A 2 kg rock is thrown vertically upwards with an initial speed of 10 m/s. Assuming no air resistance, which of the following is the maximum height reached by the rock?
3 m
4 m
5 m
6 m
Choose your answer
Did this page help you?
A soccer player kicks a soccer ball at rest on the penalty spot. The player's kick exerts a force of 43 N on the ball in the direction of travel. The ball has 862 J of kinetic energy just before the goalkeeper catches it. Which of the following is a best estimate of the distance traveled by the ball from the penalty spot to the goalkeeper's arms.
Choose your answer
Did this page help you?
A block of mass slides down an inclined plane with a coefficient of kinetic friction of
. If the angle of incline is
from the horizontal, and the block slides a distance of
, which of the following is correct for the energy dissipated by friction?
Choose your answer
Did this page help you?
A forklift truck raises a 350 kg crate from the ground to a shelf 5.0 m higher.
The forklift is 60% efficient.
Which of the following is most nearly the work done by the forklift's engine?
10 000 J
20 000 J
30 000 J
40 000 J
Choose your answer
Did this page help you?
An object is released from rest and slides a distance down an incline plane at an angle of
to the horizontal. It experiences a constant friction force with magnitude
and reaches a final speed of
.
Which of the following expressions is equal to the mass of the object?
Choose your answer
Did this page help you?
A 5 kg mass rests on a smooth, frictionless table, connected by a light inextensible string to a 3 kg mass suspended over the edge of the table. The string runs over an ideal pulley (massless and frictionless). When the 3 kg mass is released, it falls, causing the 5 kg mass to slide along the table.
If the system starts from rest, what will be the speed of both masses after the 3 kg mass has fallen 1.5 m?
3.4 m/s
4.1 m/s
5.5 m/s
5.9 m/s
Choose your answer
Did this page help you?
Two masses, and
are suspended from either side of a pulley with diameter
, where
.
In the time taken for the speed of to increase from
to
, the pulley has rotated by 180°.
Which of the following expressions is equal to the fraction ?
Choose your answer
Did this page help you?
4 constant forces act on an object which is initially at rest, as shown in the figure above.
After the object has moved at an angle of
to the horizontal, which of the following is most nearly its kinetic energy?
100 J
210 J
240 J
420 J
Choose your answer
Did this page help you?
Two objects are connected via a light inextensible string which runs over a pulley on a cliff edge. One object of mass is held stationary on the ground, as shown in the figure above, while the object of mass
is submerged under water while hanging from the string. The masses are such that
and the density of mass
is 8 times the density of water.
When is released, the string remains taut and
reaches a speed
once it has moved distance
. The coefficient of kinetic friction between mass
and the ground is
.
Which of the following is the correct expression for speed ?
Choose your answer
Did this page help you?