Force Fundamentals
What is the unit used to measure force?
Newtons
What do we call forces that are equal in size and opposite in direction?
Balanced forces
What is the unit used to measure mass?
Kg
What does friction do to the movement of objects?
It opposes movement between surfaces.
What happens to a spring when a mass is hung from it?
It extends or stretches.
Which instrument is used to measure force?
Newton balance
A box has 8 N pushing left and 8 N pushing right. What is the resultant force?
0 N
What is weight?
The force of gravity acting on an object.
Give one example of how friction can be decreased.
Lubricating moving parts, for example using oil.
In which direction does the weight force act on an aeroplane?
Vertically downwards.
Give two changes that a force can cause to an object.
Change speed, direction or shape
An object is stationary and remains stationary. What can you say about the forces acting on it?
The forces are balanced.
What equation is used to calculate weight?
Weight = mass × gravitational field strength (\(W = m \times g\))
Give one example of how friction can be increased.
Using shoe treads, roughening a surface or using bicycle brakes.
What is the name of the force that pushes an aeroplane forwards?
Thrust
Friction is an example of what type of quantity?
A force
A trolley has 10 N acting left and 6 N acting right. What is the resultant force?
4 N to the left
A pupil has a mass of 4 kg. Calculate their weight on Earth using \(g = 10\text{ N/kg}\).
40 N
Two objects have different masses but the same material. Why might the larger object be more likely to float?
It may have a lower average density and displace enough water to float.
A ball has a mass of 1.5 kg. Using g = 10 N/kg, calculate its weight.
15N
What is a force?
A push or a pull acting on an object.
A rocket has an upthrust of 2,000 N and a weight of 1,500 N. What is the resultant force, and in which direction?
500 N upwards.
A space probe has a mass of 2 kg on Jupiter, where g = 23N/kg. Calculate its weight.
46 N
What is the name of the upward force exerted by a liquid on an object in it?
Upthrust
When plotting a graph of mass against weight, which quantities and units should be shown on the axes?
Horizontal axis: mass (kg). Vertical axis: weight (N).