Definitions

Question 1

Scalar

Answer 1

A quantity with magnitude only.

Question 2

Vector

Answer 2

A quantity with magnitude and direction.

Question 3

Contact force

Answer 3

A force exerted when objects are physically touching.

Question 4

Non contact force

Answer 4

A force exerted when objects are physically separated.

Question 5

Centre of mass

Answer 5

A point where the weight of an object may be considered to act. Usually in the middle of the object.

Question 6

Work done

Answer 6

The energy Transferred by a force.

Question 7

Extension

Answer 7

How much an object has increased in length.

Question 8

Moment

Answer 8

The turning Effect of the force

Question 9

Distance

Answer 9

How far an object moves

Question 10

Displacement

Answer 10

Distance and direction from the start point to the finish point, in a straight line.

Question 11

Speed

Answer 11

How far an object moves per second

Eg 5m per second

Question 12

Velocity

Answer 12

Speed in a specific direction

Question 13

Acceleration

Answer 13

The rate of change of velocity

Question 14

Acceleration due to gravity

Answer 14

9.8 m/s2

Question 15

Terminal velocity

Answer 15

The velocity when the resultant force equals 0.
Eg when the air resistance is equal to the gravitational acceleration. Both act against each other and the resultant force is zero.

Question 16

Newton’s first law

Answer 16

If the resultant force is zero, then an object will continue to move at the same velocity.

Question 17

Newton’s second law

Answer 17

The acceleration of an object is proportional to the resultant

Question 18

Newton’s third law

Answer 18

When two objects interact, the forces that they exert on each other are equal and opposite.