Push & Pull Forces
A push or pull to the right causes an object to move in which direction?
Right
What is gravity?
A force which pulls objects towards Earth.
When a ball is rolled across the ground, it will eventually come to a stop. Explain why this occurs.
Friction slows the ball by acting against the rolling force.
What is an example of a magnet in the classroom?
The whiteboard eraser.
Define the term 'speed'.
How fast an object is moving; the rate of change of distance.
A tennis ball is sitting on smooth ground at rest. Explain what will happen to the ball if a force pushes it to the left.
It will roll to the left of its original position.
Dropped objects always fall down towards the ground. Explain why gravity makes objects fall 'down'.
The Earth's gravity pulls objects towards its centre.
Describe how friction works.
Texture or particles rub against each other, sometimes interlocking or colliding, ultimately slowing the movement of objects.
Define the term 'magnet'.
An object that produces a magnetic field.
What is velocity?
Both the speed AND DIRECTION of an object.
What is the unit we use to measure force? (Like how we measure length in metres (m), for example).
Newtons (N)
Identify whether gravity is a contact or non-contact force. Provide an example that supports your answer.
Non-contact. Miss Calitz to approve examples.
What is air resistance?
Friction with particles in the air, slowing the movement of objects in the air.
Are magnetic forces contact or non-contact forces?
Non-contact.
What is acceleration?
When an object is speeding up/increasing in speed or velocity/begins to move.
What equipment do we use to measure the size of a pulling force?
A spring balance.
What is the acceleration of gravity on Earth?
9.8 m/s/s
Describe two ways in which friction can be reduced.
Any 2 of: Wheels/rounded surfaces that roll, smooth surfaces with little texture, lubrication (water or oil etc.).
What is the term for the pull when two opposite poles of magnets are near each other?
Attraction
A car is approaching a red traffic light and slowing down. Which term best describes its motion?
Deceleration
If you push or pull an object, you are applying a contact force. There are other forces considered non-contact forces. Provide 3 examples of non-contact forces.
Gravity, magnetic forces, electrostatic forces.
Why does the Moon have less gravity than Earth?
It has less mass (is much smaller) --> greater mass = greater gravitational pull.
Skydivers fall through the air quickly when they jump from the plane. Parachutes are used to slow their fall before they land. Explain why using a parachute reduces the speed of the skydiver.
The parachute provides a large surface area to maximise air resistance with particles in the air and slow the skydiver down using this friction with the air, which opposes the downwards force of gravity.
What is the term for the push when two of the same poles of magnets are near each other?
Repulsion.
What occurs when a falling object reaches terminal velocity?
It falls at a constant speed.