NEWTON’S LAWS
A force that opposes motion between two surfaces.
friction
The type of charge carried by electrons.
negative charge
A quantity with both magnitude and direction.
The energy an object has because of its motion.
kinetic energy
Why is it harder to walk on ice than on tar?
less friction
Newton’s First Law is also known by this name.
Law of Inertia
Two positive charges brought close together will do this.
repel
The rate of change of velocity.
acceleration
The unit used to measure energy.
the joule
Why do passengers fall forward when a car suddenly stops?
Inertia
According to Newton’s Second Law, acceleration increases when this increases.
net force
The region around a magnet where magnetic forces act.
magnetic field
Displacement differs from distance because displacement includes this.
direction
The rate at which work is done.
power
Why is it easier to push an empty trolley than a full trolley?
Less mass/inertia
Newton’s Third Law states that for every action there is this.
an equal and opposite reaction
An electromagnet only becomes magnetic when this is flowing.
electric current
The gradient of a velocity-time graph represents this quantity.
acceleration
When work is done against gravity, this type of energy increases.
gravitational potential energy
Why do seatbelts help protect passengers during accidents?
increasing stopping time to reduce force
A 5 kg object accelerates at 4 m·s⁻². Calculate the net force.
20 N
Name TWO ways to increase the strength of an electromagnet.
increasing the current and increasing the number of coils
An object starts from rest and accelerates at 2 m·s⁻² for 5 s. Calculate the final velocity.
10 m·s⁻¹
A 10 N force moves an object 4 m in the direction of the force. Calculate the work done.
40 J
Why does a sharp knife cut better than a blunt knife?
greater pressure due to smaller surface area