Kinematics

Question 1

What is the equation for speed?

Answer 1

Speed = distance ÷ time

Question 2

What is the unit for speed?

Answer 2

Metres per second (m/s)

Question 3

What does a distance–time graph’s gradient represent?

Answer 3

Speed

Question 4

What does a flat (horizontal) line on a distance–time graph mean?

Answer 4

The object is stationary

Question 5

What does a steeper gradient mean on a distance–time graph?

Answer 5

Faster speed

Question 6

Define velocity.

Answer 6

Speed in a given direction

Question 7

What is the equation for acceleration?

Answer 7

a = v - u ÷ t (change in velocity ÷ time)

Question 8

What is the unit of acceleration?

Answer 8

m/s²

Question 9

On a velocity–time graph, what does the gradient represent?

Answer 9

Acceleration

Question 10

On a velocity–time graph, what does the area under the line represent?

Answer 10

Distance travelled

Question 11

State Newton’s First Law.

Answer 11

An object remains at rest or moves with constant velocity unless acted upon by a resultant force.

Question 12

State Newton’s Second Law.

Answer 12

Resultant force = mass × acceleration (F = ma)

Question 13

State Newton’s Third Law.

Answer 13

For every action, there is an equal and opposite reaction.

Question 14

What is weight?

Answer 14

The force of gravity on an object; W = mg

Question 15

What is the unit for force?

Answer 15

Newton (N)

Question 16

What does a free-body diagram show?

Answer 16

All forces acting on an object, with arrows showing size and direction

Question 17

What is resultant force?

Answer 17

The single force that has the same effect as all the forces acting together

Question 18

What is stopping distance?

Answer 18

Thinking distance + braking distance

Question 19

What factors affect thinking distance?

Answer 19

Reaction time (affected by tiredness, alcohol, drugs, distractions, speed)

Question 20

What factors affect braking distance?

Answer 20

Speed, mass of vehicle, road conditions, brake condition, tyre grip

Question 21

What is the equation for momentum?

Answer 21

p = mv

Question 22

What is the principle of conservation of momentum?

Answer 22

In a closed system, total momentum before = total momentum after a collision/explosion

Question 23

What happens in an elastic collision?

Answer 23

Momentum and kinetic energy are conserved

Question 24

What happens in an inelastic collision?

Answer 24

Momentum is conserved, but kinetic energy is not

Question 25

What happens when an object falls through a fluid like air?

Answer 25

Weight > air resistance → object accelerates; then air resistance increases until weight = air resistance → terminal velocity

Question 26

Why does a parachute slow a skydiver down?

Answer 26

It increases surface area, increasing air resistance, reducing terminal velocity