Linear Motion

Question 1

What is a scalar quantity?

Answer 1

When measurements only describe size or magnitude

Question 2

What are examples of scalar quantities?

Answer 2

Mass
Distance
Speed

Question 3

What are vector quantities?

Answer 3

When measurements are described in terms of magnitude (size) and direction

Question 4

What are some examples of vector quantities?

Answer 4

Weight
Acceleration
Displacement
Velocity
Momentum

Question 5

How do we draw vectors?

Answer 5

We usually draw then with an arrow, starting at the application point. It continues in the direction, and the length is determined by thr magnitude. The longer the arrow, the bigger the size

Question 6

What is mass?

Answer 6

A scalar quantity. It expressed the amount of substabce in our body in kg. It therefore does not have direction

Question 7

What is weight?

Answer 7

A vector quantity. This is force on given mass due to gravity. It is measured in newton’s.
Mass x gravity = weight. It therefore shows magnitude and direction

Question 8

What is distance?

Answer 8

A scalar quantity. It is the length of the path the body follows when moving from one point to another. This just measures magnitude

Question 9

What is displacement?

Answer 9

A vector quantity. It is the length in a straight line joining the start to the finish. It therefore has magnitude and direction

Question 10

What is speed?

Answer 10

A scalar quantity. It is the rate of change of distance
Speed = distance ÷ time taken
It is measured in m/s

Question 11

What is velocity?

Answer 11

A vector quantity. It is how fast a body travels in a certain direction. It is the rate of change of displacement. It has direction and magnitude.
Velocity = displacement ÷ time
It is measured in m/s

Question 12

What is acceleration?

Answer 12

A vector quantity. It is the rate of change of velocity. When velocity increases, this is positive acceleration. When velocity decreases, it is negative acceleration. This is measured in metres per second squared. M/s²
Acceleration = change in velocity ÷ time

Question 13

How do you calculate change in velocity (acceleration) in a certain time frame?

Answer 13

(Final velocity - initial velocity) ÷ time

Question 14

What is momentum?

Answer 14

The quantity of motion possessed by an object.
Mass x velocity. It is expressed as kgm/s. It is therefore a vector quantity. As mass is constant an increase in velocity will increase momentum

Question 15

What is impulse?

Answer 15

Force applied to change the momentum of an object in a certain time. Applying force in more time or increased impulse leads to a larger change in momentum. Force x time Force is applied for

Question 16

What can impulse be?

Answer 16

Positive or negative

Question 17

What is positive impulse in running

Answer 17

Application of action force causing the foot to be driven off the ground

Question 18

What is positive impulse?

Answer 18

Force applied to increase velocity of an object

Question 19

What is negative impulse?

Answer 19

Force applied to decrease the velocity of an objrct

Question 20

What is negative impulse in running?

Answer 20

It occurs when the foot hits the ground as velocity of foot reduces

Question 21

What are the rules for drawing impulse graphs?

Answer 21

-Force along the side time along the middle
-Each axis shown as an arrow
-0 in the middle of the down arrow
-Negative impulse shown first below the 0, then positive impulse
-Impulses must be labled as a plus or negative

Question 22

What is net impulse?

Answer 22

A combination of positive and negative impulse

Question 23

How is impulse represented?

Answer 23

Represented by an area under a force-time graph.

Question 24

What are distance time graphs?

Answer 24

They show the distance traveled over a period of time.
If the line doesn’t move, there is no distance traveled
If the line is diagonal, it indicated distance run is constant
If the line is curved it means more or less distance is being covered in a certain amount of time (acceleration or deceleration)

Question 25

How do you work out the gradient of a graph?

Answer 25

Change in y ÷ change in x

Question 26

What are velocity time graphs and speed time graphs?

Answer 26

The shape of the graphs will represent the same pattern of motion in both graphs. They indicate the velocity or speed of a performer or object per unit of time. A straight line shows constant volecity A graph curved up indicates acceleration. Gradient = change in velocity ÷ time Graphs curved down indicates deceleration