Types of Forces
Which type of force pulls objects towards the Earth?
Gravity
True or false. An object must have a force pushing it forward to keep moving at a constant speed.
False
Complete the sentence:
A force is a __________ or a __________ that can change the motion or shape of an object.
Push or pull
What are the 6 types of simple machines?
- pulley
- screw
- wheel and axle
- inclined plane
- wedge
- lever
Match each tool or weapon to its main purpose.
Tool or Weapon Purpose
Boomerang a) Digging for food
Spear b) Hunting animals
Coolamon c) Carrying food, water, or babies
Digging stick d) Throwing and returning (for some types) or hunting
Boomerang D
Spear B
Coolamon C
Digging Stick A
Which statement best describes gravity?
A. A force that pushes objects away from the Earth.
B. A force that pulls objects towards the Earth.
C. A force that only acts on moving objects.
D. A force created by magnets.
B
What is Ms. Dubois' favourite colour?
Purple
A hockey puck slides across the ground and gradually slows down. Which force is mainly causing it to slow?
A ball is thrown straight up into the air. After it leaves your hand, which force acts on the ball (ignoring air resistance)?
A. An upward force from your hand
B. Gravity only
C. Gravity and an upward pushing force
D. No forces act on the ball
B. Gravity only as we ignore air resistance.
What is a force?
Push, pull or twist
Match the type of lever with the example:
1st Order
2nd Order
3rd Order
Wheelbarrow, scissors, tweezers
1st Order - scissors
2nd Order - wheel barrow
3rd Order - tweezers
Compare a traditional Aboriginal spear with a modern fishing rod.
Explain:
Various answers
What is gravity?
A force that pulls objects to the centre of masses.
When did Ms. Dubois come to Cecil?
Explain the difference between contact forces and non-contact forces. Give two examples of each.
Contact force requires objects to touch. Non-contact force does not.
A student says:
"A heavier object falls faster than a lighter object because gravity pulls harder on it."
Do you agree or disagree? Explain your answer using what you know about gravity and falling objects.
Disagree - all objects fall at the same rate due to gravity. Air resistance is the reason feathers/ leaves fall slowly not because gravity affects them differently.
Decide whether a force is being applied. Explain your answer.
Yes - push force as well as friction acting opposite.
Match the most suitable simple machine to each task.
a) Lifting a bucket from a well
b) Splitting a log
c) Moving a heavy crate into a truck
d) Tightening two pieces of wood together
a) Pulley
b) Wedge
c) Inclined plane
d) Screw
Which statement best explains why Aboriginal peoples used different tools and weapons in different parts of Australia?
A. All Aboriginal groups used exactly the same tools.
B. The tools and weapons were designed to suit the local environment and available resources.
C. Metal tools were available in some regions but not others.
D. Tools were only used for hunting.
B
A tennis ball and a basketball are dropped from the same height at the same time.
Ignoring air resistance:
They both hit the ground at the same time.
How many children does Ms. Dubois have?
2
A toy car is pushed across a floor. It starts moving quickly but eventually stops. Identify at least three forces acting on the toy car while it is moving.
Push force/ applied force.
Friction.
Gravity.
Two students are discussing a book resting on a table.
Who is correct?
Student B.
Decide whether a force is being applied. Explain your answer. A soccer ball rolls across the grass and slows down.
Friction is acting on the ball to oppose the motion.
A construction worker needs to lift a heavy bucket of bricks onto a roof.
Choose two different simple machines that could help with this task.
A pulley
An inclined plane
Traditional Aboriginal tools were often made from natural materials such as wood, stone, bone, plant fibres, and animal sinew.
Choose two of these materials and explain why each was useful for making tools or weapons.
Various answers
An astronaut weighs much less on the Moon than on Earth.
Explain why this happens, even though the astronaut's mass stays the same.
The weight is the force that we feel. It changes depending on the size of the planet. A smaller planet has a smaller force due to gravity.
How long has Ms. Dubois been wearing a scarf?
A student pushes a box across the classroom floor with a force of 20 N. Friction acts on the box with a force of 15 N in the opposite direction. What is the resultant (net) force acting on the box?
5 N forward
A car is travelling at a constant speed along a straight, level road.
A student says:
"The engine force must be greater than all the other forces because the car is moving."
Using your knowledge of balanced and unbalanced forces:
Explain whether the student's statement is correct.
May be true. If the car is accelerating then true. If the car is moving at constant speed then it is balanced.
A student writes:
"A force is anything that makes an object move."
What is wrong with this definition?
It might also keep things stopped like gravity acting on a book on a table.
Why does using a ramp make it easier to move a heavy box into a truck than lifting it straight up? Use the idea of force in your explanation.
Because the same force is spread over a longer distance.
You are travelling through the Australian bush and need to collect food and carry it back to camp.
Which two traditional Aboriginal tools would be most useful?
Various answers
A skydiver jumps from an aeroplane.
Describe how the forces acting on the skydiver change:
Various answers.
What senior subject does Ms. Dubois teach?
Physics