End of topic quiz.

1
End of topic quiz.

• Click once to change the slide. The question will
  come up automatically.
• Click again only when you have written down your
  answer.
• Correct your answers, taking note of the ones you
  got wrong.
• It would be a good idea to print the slides with
  the questions you got wrong. You can then discuss
  them with your teacher.

2
1. What is a force?

• A force is a push or a pull.

3
2. Draw and name the forces acting on a block of
wood floating on water.
Upthrust
Weight
4
3. Draw and name all the forces acting on a car
that is increasing its speed as it moves along
the road.
Contact / Reaction forces
Thrust
Drag
Weight
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4. Fill in the blanks

• ________ is a force that acts on a mass due to
  gravity.
• An object that has a mass of 1kg, will have a
  ______ of 10 _________ on Earth.
• The gravitational field on the moon is ______
  times _________ than on the Earth.
• The same object will have the same ______ on the
  Moon, but a _________ ________ .
• If the object was launched into space it would be
  ____________.

Weight
weight
Newtons
six
smaller
mass
smaller
weight
weightless
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Qu. 5
c) Satellites are quite new to us when we
consider how long we have been trying to
investigate outer space. How has this technology
changed what we know? We know more, we can look
further, we can get clearer images. We have
realised that we dont know everything! What else
can satellites be used for? Communication, cable
television, spying, weather forecasting.
a) The picture shows a satellite orbiting the
Earth. What keeps it in its orbit? Gravity. b)
Another satellite is placed in a higher orbit.
How would the forces on the two satellites
compare? The gravitational force on the satellite
that is further away will be weaker.
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For each of the statements below, decide whether
the object is being acted upon by balanced or
unbalanced forces.

• 6. A car rolling down a hill at a constant speed.
• 7. An aeroplane rolling to a stop on a runway.
• 8. An apple falling from a tree.
• 9. A book resting on a table.
• 10. A tennis ball, just as it is struck by the
  racquet.
• 11. A conker being whirled around on its string.

BALANCED FORCES UNBALANCED FORCES UNBALANCED
FORCES BALANCED FORCES. UNBALANCED
FORCES UNBALANCED FORCES
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12. Determine the size and direction of the
resultant force shown for each diagram. State
what the object will do as a result.
Click to see the rest of the question
3N
The trolley is moving at a constant speed of 1m/s
(indicated by the green arrow) when
The resultant force 3N acting to the left. The
trolley will slow down, maybe even stop then
start rolling the other way.
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13. Determine the size and direction of the
resultant force shown for each diagram. State
what the object will do as a result.
Click to see the rest of the question when you
are ready
5N
1N
The trolley is moving at a constant speed of 1m/s
(indicated by the green arrow) when
The resultant force 4N acting to the right. The
trolley will speed up.
10
14. Determine the size and direction of the
resultant force shown for each diagram. State
what the object will do as a result.
Click to see the rest of the question when you
are ready
5N
5N
The trolley is moving at a constant speed of 1m/s
(indicated by the green arrow) when
The resultant force 0N . The trolley will
continue to move in a straight line at 1m/s.
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15. LAST QUESTION!!
The height from which the object is dropped. What
the object is moving through (air or water for
example) The material on the outside surface of
the object.

• You have to plan an experiment to see how the
  surface area affects the speed of a falling
  object.
• What two things would you have to measure in
  order to calculate the average speed of the
  falling object?
• Suggest what equipment might be appropriate for
  measuring these things in your experiment.
• List two things that you should keep the same in
  order to carry out a fair test.
• One group recorded 5.5s for an object to fall
  from 1m, then 4.0s for the same object to fall
  from 2m. They think that the times recorded are
  inaccurate. Suggest what could be done to
  increase the accuracy of each test.

The test should be repeated two or three times
from the same height. You could then find the
average time.
A long measuring tape, or metre rule, and a
stopwatch or light gates.
You have to measure the total distance fallen,
and the time taken