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Unit summary

Revise!

1. Determine the forces acting on objects in the 6. The mass of a crow equals 700 g.
photo.
a) What is the weight of the crow sitting on a
tree branch?
textbooks nis edu kz
b) What is the weight of the flying crow?

c) Does gravity act on the flying crow?

7. The maximum load of a certain rope is 2000 N.
Can this rope tolerate lifting the following loads
only one by one, or can it bear the weight of
everything at once?
● 30 bricks of 6 kg each

● a 0.3-tonne concrete plate

● 15 buckets of paint weighing 10 kg each
8. An astronaut lands on the Moon. On the Earth,
he has a weight of 600 N. His weight on the
Moon equals 100 N.

a) What is the mass of this astronaut?

b) Why does his weight change?
c) What is the acceleration of gravity on the
Moon?

2. What affects the force of gravity on Earth?

3. The lightest bones in the human body are the
auditory ossicles: malleus, incus and stapes. What
is their weight if their mass is 0.02 g?

4. A shopper bought 2 kg apples, 1.5 kg pears, 600 g
nuts and 300 g raisins. Calculate the total weight
of their shopping.
5. Two parcels weighing 5 kg each were sent
from London to Astana. The Royal Mail charges
according to the size and mass of each package.
Why do you think that is?

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