Dynamics S3

Question 1

SPEED

Answer 1

The distance travelled each second

Question 2

Average speed

Answer 2

The total distance travelled by an object at a particular moment in time

Question 3

Instantaneous speed

Answer 3

The speed of an object at a particular moment in time

Question 4

Acceleration

Answer 4

The change in speed each second. It is given by the gradient of the line on a speed-time graph

Question 5

Deceleration

Answer 5

A negative acceleration which indicates that an object is slowing down

Question 6

Force

Answer 6

An interaction between two objects that can change an object’s shape, speed, direction. It is measured in Newtons(N)

Question 7

Newton Balance

Answer 7

A device with a scale in newtons that can be used to measure forces

Question 8

Contact force

Answer 8

A force applied to an object by another body that is in direct contact with it. E.g. a push, pull, twist

Question 9

Non-Contact

Answer 9

A force applied to an object by another body that is not in direct contact with it. E.g. gravity, magnetism or electrostatic

Question 10

Friction

Answer 10

A force which opposes the motion of an object

Question 11

Air resistance

Answer 11

A frictional force caused by air particles coming into contact with an object

Question 12

Balanced forces

Answer 12

When the forces acting on a object are equal in magnitude but opposite in direction

Question 13

Unbalanced forces

Answer 13

When the forces acting on an object are different in magnitude but opposite in direction

Question 14

Mass

Answer 14

The quantity of particles that make up an object. It is measured in kilograms(kg)

Question 15

Weight

Answer 15

The force due to gravity acting on an object. It is measured in newtons (N)

Question 16

Gravitational Field Strength

Answer 16

The gravitational force per unit mass. On Earth, g is 9.8Nkg

Question 17

Newton’s 1st law

Answer 17

An object will remain at rest or move at a constant speed in a straight line unless acted on by an unbalanced force

Question 18

Newton’s 2nd law

Answer 18

The forces acting on an object are unbalanced, the object will accelerate in the direction of the unbalanced force

Question 19

Free-fall

Answer 19

Describes the movement of any object under the influence of gravity alone

Question 20

Terminal Velocity

Answer 20

For an object in free-fall, a constant speed is reached when the upward force on the object(air resistance) is balanced by the downward force on the object(weight)

Question 21

Newton’s 3rd law

Answer 21

I f an object A exerts a force on object B, then B exerts an equal but opposite force on A

Question 22

Newton Pairs

Answer 22

Action and reaction forces for a specific situation involving Newton’s 3rd law