Unit 2 & 6

Question 1

Instantaneous Speed

Answer 1

The speed of an object at an instant in time; the rate of change in position with respect to time

Question 2

Average speed

Answer 2

The average speed of a journey = total distance divided by total time

Question 3

Acceleration

Answer 3

the rate of change of velocity respect to time

Question 4

Air Resistance

Answer 4

The transfer of energy into a fluid from an object moving in it

Question 5

Translational Equilibrium

Answer 5

A body is in translational equilibrium when the sum of all the external forces acting on it equals zero

Question 6

Newton’s First Law

Answer 6

A body will remain at constant velocity unless acted upon by a resultant external force

Question 7

Inertia

Answer 7

The property of matter by which it continues in its existing state of rest or uniform motion in a straight line unless that state is changed by an external force.

Question 8

Newton’s Second Law

Answer 8

The resultant external force acting on a body is proportional to the rate of change of momentum of the body

Question 9

Newton’s Third Law

Answer 9

When body A exerts a force on body B, body B exerts a force on body A that is equal in magnitude and opposite in direction

Question 10

Static Friction

Answer 10

the friction when there is no relative movement between the surfaces.

Question 11

Dynamic Friction

Answer 11

the friction when there is relative movement between the surfaces

Question 12

Kinetic Energy

Answer 12

the energy an object has because of its motion.

Question 13

Gravitational Potential Energy

Answer 13

the energy an object has because of its position in a gravitational field.

Question 14

Elastic Potential Energy

Answer 14

energy stored as a result of the deformation of an elastic object/the work done to stretch the spring.

Question 15

Work Done

Answer 15

force exerted * distance moved in the direction of the force

Question 16

Power

Answer 16

the rate of energy transfer

Question 17

Principle of Conservation of Energy

Answer 17

energy cannot be created or destroyed, only transferred form one form to another.

Question 18

Momentum

Answer 18

The product of an object’s mass and velocity, measured in kg m s-1

Question 19

Impulse

Answer 19

The change of an object’s momentum, measured in kg m s-1

Question 20

Collision

Answer 20

an interaction where momentum transfers.

Question 21

Principle of Conservation of Momentum

Answer 21

Total momentum of a system is always constant provided no external force acts

Question 22

Elastic Collision

Answer 22

A collision where kinetic energy is conserved.

Question 23

Period

Answer 23

the time taken for the object to go round the circle once.

Question 24

Frequency

Answer 24

the number of times the object goes around the circle each second.

Question 25

Angular displacement

Answer 25

the angle moved around the circle by an object form where its circular motion starts.

Question 26

Angular Velocity

Answer 26

angular displacement/ time for displacement to happen.

Question 27

Newton’s Law of Gravitation

Answer 27

the force of attraction between two objects is proportional to the product of the masses and inversely proportional to the square of their separation.

Question 28

Gravitational Field Length

Answer 28

the force per unit mass experienced by a small point mass placed at that point.