New
New
Year 10
AQA
Foundation

# Acceleration (a = Δv/t)

I can calculate the acceleration and deceleration of objects.

New
New
Year 10
AQA
Foundation

# Acceleration (a = Δv/t)

I can calculate the acceleration and deceleration of objects.

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## Lesson details

### Key learning points

1. Acceleration is equal to the amount that velocity changes in one second.
2. Acceleration is the rate of change of velocity.
3. Average acceleration = change of velocity / time (a = Δv/t)
4. An object that is slowing down is decelerating.
5. An object that is decelerating has a negative acceleration.

### Common misconception

Pupils often think that if velocity or speed is increasing, then acceleration must also be increasing. Pupils often don't associate a change in direction at a constant speed with an acceleration.

Before teaching acceleration, consolidate an understanding of the differences between velocity and changes in velocity. Discuss how an object can be accelerating AND travelling at a constant speed (circular motion).

### Keywords

• Acceleration - The acceleration of an object is the rate of change of velocity. This is how much the velocity changes per second.

• Deceleration - Deceleration is used to describe a change in velocity where the object slows down.

• Velocity - The velocity of an object is the speed in a particular direction. This is the rate of change of displacement.

• Delta v (Δv) - The change in velocity is represented by 𝚫v.

• Rate of change - A rate of change is how much a quantity is changing by every second.

### Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

## Starter quiz

### 6 Questions

Q1.
Which international standard unit is used to measure speed and velocity in physics? Give the symbols.
Correct Answer: m/s, metres per second, metres/s, metres/second
Q2.
A roller-skater covers a distance of 520 m in 40 s. Calculate his speed.
0.08 m/s
2.6 m/s
480 m/s
20 800 m/s
Q3.
Which of these is a vector quantity?
distance
mass
speed
volume
Q4.
A lorry is travelling along a straight road. Its speed increases from 5.6 m/s to 8.4 m/s. What is the change in velocity for the lorry?
8.4 m/s
5.6 m/s
0 m/s
-2.8 m/s
Q5.
How far will a wind-up toy travel if it has a speed of 0.02 m/s and it moves for 1 minute?
Correct Answer: 1.2 m, 120 cm, 1.2 metres, 1.2 metre, 120 centimetres
Q6.
How long will it take a rocket traveling at 5.0 km/s to travel a distance of 500 m?
25 s
10 s
1.0 s
0.25 s

## Exit quiz

### 6 Questions

Q1.
Match the key words and phrases to their explanations.
Correct Answer:velocity,how fast something is moving in a particular direction

how fast something is moving in a particular direction

Correct Answer:rate of change,how much a quantity changes each second

how much a quantity changes each second

Correct Answer:acceleration,the rate of change of velocity

the rate of change of velocity

Correct Answer:deceleration,a change in velocity where the object is slowing down

a change in velocity where the object is slowing down

Correct Answer:delta v (𝚫$$v$$),a symbol used to represent change in velocity

a symbol used to represent change in velocity

Q2.
Match the quantities to the unit definitions.
Correct Answer:velocity,a vector measured in m/s

a vector measured in m/s

Correct Answer:distance,a scalar measured in m

a scalar measured in m

Correct Answer:acceleration,a vector measured in m/s$$^2$$

a vector measured in m/s$$^2$$

Correct Answer:speed,a scalar measured in m/s

a scalar measured in m/s

Correct Answer:displacement,a vector measured in m

a vector measured in m

Q3.
Which of these equations correctly give acceleration ($$a$$)?
acceleration = change in velocity + time
Correct answer: acceleration = change in velocity ÷ time
acceleration = change in velocity × time
Correct answer: $$a = {\Delta v \over t}$$
$$a = {\Delta v \times t}$$
Q4.
A car takes 17.6 s to accelerate from 0 m/s to 44 m/s. Calculate the acceleration of the car in m/s$$^2$$. You do not need to enter the unit.
Correct Answer: 2.5, 2.5 m/s^2, 2.5 m/s2
Q5.
A motorcycle reduces its velocity from 25 m/s to 14 m/s in 5.5 s. What is the size of the deceleration?
Correct answer: -2.0 m/s$$^2$$
-7.1 m/s$$^2$$
-11 m/s$$^2$$
-44.5 m/s$$^2$$
-49.5 m/s$$^2$$
Q6.
An arrow is travelling at 20 m/s. It hits a target and slows to 2.0 m/s in a time of 0.2 s. Calculate the acceleration during the impact with the target. You do not need to enter the unit.
Correct Answer: -90, 90, -90 m/s^2, 90 m/s^2