Uploaded by Sian Geldenhuys

Year 7 Forces revision sheet 2018

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Year 7 Revision
1. What is a force?
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2. A push is a force of ________________ (PULRESION) where objects get _________
(THUFURRE) apart and a pull is a force of _________________ (ATRTCINOAT) where
objects get ____________ (SLOCER) together.
3. Explain the difference between a contact and a non-contact force:
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4. list two examples of contact forces and two examples of non-contact forces:
Contact forces:


Non-contact forces:


5. For each of the images below, decide whether the forces on the object are balanced
or unbalanced and state the direction it will move.
5N
25 N
20 N
5N
12 N
10 N
5N
Balanced or unbalanced
Direction -
Balanced or unbalanced
Direction -
Balanced or unbalanced
Direction -
6. Explain what a friction force is.
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7. State one example of a situation where friction is helpful and explain what would
happen if there was no friction involved.
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8. Explain why your shoes get holes in them if you wear them for a long time.
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9. Explain why your hands get warmer when you rub them together.
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10.What is an example of a situation where you would want friction to produce heat?
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11.What is an example of a situation where you would want friction to produce wear?
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12. Steve the caveman is trying to move his fridge to the other side of his cave.
The issue is that there is far too much friction between
the fridge and the ground and Steve can’t move it.
At the moment the fridge is full of heavy dinosaur
steaks and the cave kitchen floor is covered in rough
gravel.
a) State two ways that Steve could reduce the amount of friction and then explain
why each of these methods would work.
Method of reducing friction: __________________________________________________
Why this reduces friction:
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Method of reducing friction: __________________________________________________
Why this reduces friction:
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b) State two other ways that friction can be reduced:
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13.Define the following terms:
Newton- ________________________________________________________________
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Magnetic field -___________________________________________________________
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Classify the following materials as either magnetic or non-magnetic:
Iron
Copper
Wood
Aluminium
Magnetic
Steel
Nickel
Non-magnetic
14. Explain why a compass needle will align to point North.
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15.Explain why a common bar magnet will not align to point North like that in a
compass.
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16.How could you make a bar magnet point North like a compass?
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17.Explain how a compass would be affected if a bar magnet was held nearby. Would
the compass still work?
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18. Indicate whether the magnets below will attract or repel each other.
A)
N
S
S
N
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B)
N
S
N
S
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19. Count the number of magnetic field lines in
each of the circles on the right.
1 - ________________
1
2- ________________
2
20. Using the information in the previous question, explain why the magnet gets weaker
as they move further away.
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