P9- Motion Flashcards

1
Q

What does the gradient of a line on a distance-time graph represent?

A

speed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What unit is speed?

A

metres per second (m/s)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what symbol is speed?

A

v

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is distance traveled measured in?

A

metres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What can the d/s*t equation be used to calculate?

A

the average speed of an object whose speed varies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What should you do in the exam when time is given in minutes or hours in these calculations?

A

always convert it into seconds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

A steeper gradient equals to a?

A

faster speed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is velocity?

A

speed in a given direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

An object that travels at constant velocity travels at what?

A

a constant speed without changing its direction (straight line)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the word used for the distance travelled in a given direction?

A

displacement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the acceleration of an object?

A

its change of velocity per second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the unit of acceleration?

A

metre per second squared (m/s^2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Any object with a changing velocity is?

A

accelerating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How can we work out average acceleration?

A

change in velocity/ time taken for the change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How to find the change in velocity?

A

final velocity-initial velocity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The equation of acceleration can be written as?

A

(final velocity - initial velocity)/ time taken for the change

17
Q

equation for acceleration as symbols?

A

a=(v-u)/t

18
Q

When is the term deceleration or negative acceleration used?

A

an object slows down

19
Q

When does a car decelerate?

A

when the driver brakes

20
Q

A minus value for acceleration means?

A

the object is slowing down

21
Q

How may you want to record how the velocity of an object changes?

A

-a motion sensor linked to a computer

22
Q

If you let a trolley accelerate down the runway, what happens?

A

its velocity increases wih time

23
Q

If the line is straight in the velocity time graph, what does this mean?

A

the increase in velocity was the same every second

-the acceleration of the trolley was constant

24
Q

What happens if you make the runway steeper for the trolley?

A

the trolely accelerates faster

25
Q

What would happen to the line on the velocity time graph if acceleration increases?

A

steeper gradient

26
Q

What does the gradient of the line on a velocity-time graph represent?

A

acceleration

27
Q

What does braking do?

A

reduces the velocity of a behicle

28
Q

What happens when a vehicle stops at a set of traffic lights?

A

the velocity is constant until the driver applies the brakes

29
Q

If the gradient of the velocity-time graph is zero, what does this mean?

A

acceleration in this section is zero

30
Q

When brakes are applied, what happens to the vehicle?

A

vehicle decelerates and its velocity decreases to zero

31
Q

What happens to the gradient of the line when brakes are applied?

A

the gradient of the line is negative

-acceleration is negative

32
Q

The area under the line on a velocity-time graph represents what?

A

the distance travelled in a given direction (or displacement)

33
Q

How can speed and velocity also be described in?

A

kilometres per hour (km/h)

34
Q

If speed and velocity are given in km/h, what must be done before plotting them on a graph or using them in?

A

their values must be converted to metres per second

35
Q

For an object moving at constant speed, what does the line in a distance-time graph look like?

A

a straight line sloping upwards

36
Q

What is the speed of the object is represented by?

A

the gradient of a line

37
Q

Why does the gradient represent acceleration?

A

change of velocity/time taken

38
Q

To find the distance travelled from the graph…

A

remember that the area under a line on a velocity-time graph represents the distance travelled

39
Q

What equation is useful for calculations where the time taken is not given and the acceleration is constant?

A

v^2 - u^2= 2as