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WorksheetsForces
Total questions: 25
Worksheet time: 31mins
Newton’s third law refers to two forces acting in a pair.These forces
act in the same direction
act on different objects.
are different types of force
have different magnitudes.
A brick of mass 5.0 kg falls through water with an acceleration of 0.90 m s–2.Which of the following can be used to calculate the resistive force acting on the brick?
5.0 × (0.90 – 9.81)
5.0 × (0.90 + 9.81)
5.0 × 0.90
5.0 × 9.81
A box is pulled along the floor using two identical ropes. The tensions in the ropes act in the directions shown and have magnitudes TP and TQ. The box moves at a constant speed in the direction shown.The magnitude of the frictional force acting on the box is equal to
TP sinθ + TQ sin2θ
TP cosθ + TQ cos2θ
TP + TQ
zero
Which of the following is the unit of upthrust?
N m−2
N m−1
N m
N
A small stone of mass m is dropped into a pond and accelerates downwards with an acceleration a. The free-body force diagram for the stone is shown.
U + D – mg = 0
U + D – mg = ma
mg – U − D = 0
mg – U − D = ma
An object of weight W is on a slope at an angle θ to the horizontal as shown. The normal contact force is R. As θ increases, R will
decrease because R = Wcosθ.
decrease because R = Wsinθ.
increase because R = Wcosθ.
increase because R = Wsinθ.
A car pulls a caravan at a slow but increasing velocity along a horizontal road.The four forces acting on the car are weight W, reaction force R of the road on the car, tension T in the tow‑bar and friction F between the car tyres and the road. Which of the following could be the free‑body force diagram for the car?
A person stands on some bathroom scales in a stationary lift. The lift begins to move upwards with a constant acceleration. The reading on the scales will
increase but then remain constant.
increase at a constant rate.
decrease but then remain constant.
decrease at a constant rate.
A child throws a ball vertically upwards and then catches it when it falls back down. When the ball is caught, the ball exerts a force on the child’s hand.According to Newton’s third law there will also be
a downwards force of the ball on the hand.
a downwards force of the hand on the ball
an upwards force of the ball on the hand.
an upwards force of the hand on the ball.
A free-body force diagram can be used to represent the forces acting on an object. Which of the following should not appear on the free-body force diagram for a block sliding down a slope?
normal reaction of ground
mass × gravitational field strength
friction
acceleration of block
The correct definition of the term centre of gravity is
all the force acts on a body
gravity acts on a body
the weight of the body may be considered to act
the weight is concentrated
A picture is hung using a wire placed over a small hook as shown.T1 and T2 are the tension forces acting on the hook. Which of the following correctly shows the vector diagram for the resultant force T of the two tensions?
Select the answer in which both quantities are vectors.
acceleration, speed
displacement, velocity
mass, time
power, weight
A force F is resolved into two components, Fh and Fv , at right angles to one another.Which statement is not true?
Decreasing teta increases the magnitude of Fh
Increasing teta increases the magnitude of Fv
Fh and Fv have magnitudes that when added together give a total equal to the magnitude of F.
Fh and Fv have magnitudes that when added together give a total greater than the magnitude of F.
A car of mass m travelling with a velocity v comes to rest over a distance d in time t. The constant frictional force acting on the car while it is braking is found using
mv/ 2t
2mv/ t
mv2/2d
2mv2/d
The newton can be written in base units as
kg m
kg m s-1
kg m s-2
kg m2 s-2
A trolley rolls down a slope from rest. The trolley moves through a vertical height h while rolling a distance s along the slope. The maximum possible speed is given by
2gs
2gh
√(2gs)
√(2gh)
An apple is at rest on the ground. The diagram shows three forces of equal magnitude.W = weight of apple P = push of apple on ground R = normal contact force of ground on apple Which row in the table shows Newton’s first and third laws being applied correctly
Below is a free-body force diagram for the balloon when a wind is blowing.The magnitude of the resultant force acting on the balloon is
400 N
500 N
700 N
9 805 N
The diagram shows an object on an inclined surface. The component of the weight W parallel to the surface is
0
1
W cos θ
W sin θ
A child goes down a slide. Which of the diagrams correctly represents the forces acting on the child?
A car pulls a trailer of weight 2500 N with a force of 20 N for a distance of 8 km along a horizontal road.How much work is done by the car in pulling the trailer?
160 J
20 000 J
160 000 J
20 000 000 J
The aeroplane is now flown at a constant altitude but an increasing speed. Which of the following pairs of forces will have the same magnitude?
drag and weight
drag and thrust
lift and drag
lift and weight
A car of known mass has a constant acceleration. The resultant force acting on the car can be found by applying
Newton’s first law
Newton’s second law
Newton’s third law
Stokes’s law
A car is towed by a truck using a rope. The car is pulled at a constant speed creating a tension T in the rope. The horizontal forces acting on the car are shown.The magnitude of the force exerted by the truck on the car is
T + F
T – F
T
zero
