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Unit summary

Check your knowledge and understanding

1. Imagine you are a pilot flying to the polar regions 4. Compare the weights and masses of 2 l of water
and you have to drop food boxes down onto and 2 l of sunflower oil. Explain your answer.
the drifting ice. What do you need to take into 5. Compare the gravitational forces acting on
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account when dropping the boxes?
100 kg of iron and 100 kg of cotton. Explain
your answer.

6. A 45 kg student going on a hiking trip takes
a backpack filled with 8 kg of supplies and
equipment. Calculate the force of gravity
operating on the student. What force does the
student exert against the ground?

2. Two vehicles – a car and a truck – are moving at
the same speed. Explain why, after shutting the
engines off, the car continues moving for 700 m
but the truck travels only 400 m.

3. There is a 30 kg toolbox on the floor. Draw a
labelled diagram showing the forces acting
on the toolbox.

Assess your learning

Reflect on how well you met the learning objectives of this unit. Use the worksheet provided by
your teachers to develop your own targets.

How confident am I?

I can …
explain the phenomenon of inertia and give examples
prove that force is a measure of the interaction between objects (action on an object)

measure force using a dynamometer
represent forces graphically using a scale

explain the difference between gravitational force and weight of an object
show the relationship between mass and weight, and solve problems using the formula W = mg

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