Conservation of momentum | Combined science | Quizalize & Oak National Academy

Starter quiz

Which of the following terms means the highest velocity of an object falling through a fluid?

top velocity

ultimate velocity

terminal velocity ✓

final velocity
Which of the following will reduce the total stopping distance of a vehicle?

higher speed

wet roads

alcohol consumption

icy roads

increased driver concentration ✓
What size resultant force will cause an object of mass 6.0 kg to accelerate at 20 m/s $^2$ ?

0.3 N

3.3 N

14 N

26 N

120 N ✓
Which of the following relationships can be used to find the acceleration $a$ of an object with mass $m$ when there is a resultant force $F$ acting on it?

$a = F × m$

$a = F + m$

$a = F - m$

$a= \frac{F}{m}$ ✓

$a = \frac{m}{F}$
A scooter and rider have a combined mass of 150 kg. Calculate their acceleration when a resultant force of 450 N acts on them.

0.33 m/s $^2$

3.0 m/s $^2$ ✓

6.0 m/s $^2$

300 m/s $^2$

600 m/s $^2$
A stone of mass 0.5 kg is falling through the air. It has a weight of 5 N and a drag force of 4 N acting upwards on it. Calculate the acceleration of the stone. You do not need to include the unit.

'2' ✓

Exit quiz

Match the following key terms to their definition.

momentum

⇔

the product of the mass and velocity of an object, $p = m × v$ ✓

kilogram metres per second (kg m/s)

⇔

the unit of momentum ✓

conservation of momentum

⇔

for a closed system, momentum is always conserved in any interaction ✓

collisions

⇔

happen when two objects move together and hit each other ✓

explosions

⇔

happen when a single object splits into pieces that move apart ✓
Starting with the smallest momentum, sort the following objects into order of increasing momentum.

1

⇔

a lorry stationary of mass 3000 kg

2

⇔

a motorcycle of mass 200 kg travelling at 20 m/s

3

⇔

a van of mass 1200 kg travelling at 10 m/s

4

⇔

a car of mass 800 kg travelling at 16 m/s
Which of the following is always correct for a closed system of objects that interact with each other?

Total momentum increases in explosion interactions.

Total momentum decreases in any collision interactions.

Total momentum is always the same before and after any interaction. ✓

Total momentum decreases in explosion interactions.

Total momentum increases in any collision interactions.
A toy aeroplane of mass 1.5 kg has a momentum of 30 kg m/s. Calculate the velocity of the aeroplane.

0.05 m/s

20 m/s ✓

28.5 m/s

31.5 m/s

45 m/s
Two stationary dynamics trolleys are separated by an explosion. Trolley A (mass = 1.5 kg) travels at 3.0 m/s after the explosion. Calculate the speed of trolley B (mass = 0.5 kg) after the explosion.

'9.0 m/s' ✓
A van (mass = 1600 kg) travelling at 5.0 m/s collides with a stationary car (mass = 900 kg) and they join together. Calculate the velocity at which they move off after the collision.

8.8 m/s

5.0 m/s

3.2 m/s ✓

1.7 m/s

0 m/s

Worksheet

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Lesson Details

Key learning points

Momentum = mass × velocity, p = mv
In a closed system, the total momentum before an event equals the total momentum after the event.

Common misconception

Pupils may assume that being able to complete calculations by substituting numbers into an equation is the same as fully understanding the relationship.

Include questions for which pupils are required to explain their understanding.

Keywords

Momentum - is the product of the mass and velocity of an object, p = m × v
Kilogram metres per second - is the unit of momentum (kg m/s)
Conservation of momentum - is the principle that states, for a closed system, momentum is always conserved in any interaction
Collisions - happen when two objects move together and hit each other
Explosions - happen when a single object splits, or combined objects separate, into pieces that move apart