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If an object is at rest, forces are...
Balanced
Give the name of the force that pulls objects toward the Earth?
Gravity
The heavier an object, the more __________ is required to stop it.
Force
What is the unit to measure forces, and its symbol?
Newton (N)
What are the two different types of forces?
Contact and non-contact forces
What effect do unbalanced forces have on an object’s motion?
Unbalanced forces change an object’s motion.
A car and a large truck are rolling down a hill. Which requires more force to stop?
The truck
An object at rest will stay at rest unless this occurs.
The object is acted upon by an unbalanced force
What is the upward force acting on an object as it falls through the air?
Air resistance
A free body diagram of an aeroplane flying through the sky would have how many arrows? Double points if you can label the arrows.
4 - gravity, air resistance, applied force, friction
Give an example of how decreasing friction is helpful.
Oiling a machine or bike, using a cart with wheels to move an object
Forces can be defined as 3 things.
A pull, push or twist
True or False: Like poles on a magnet attract.
False - opposites attract
Give an advantage (example) of friction?
It holds your feet on the ground while you walk; It allows cars to brake; Friction holds a nail in the wall/ceiling; It helps to hold a glass or grip a pencil.
The more mass an object has the more _________ it has.
Inertia
What is used to measure force?
Using a spring balance / Newton metre / force metre
When an object moves through the air, air resistance acts in which direction?
In the opposite direction to movement
Snails produce mucus (slime) to help them move along the ground. How does the mucus help snails move?
Mucus reduces friction. It acts as a lubricant.
Give the name of two forces that slow down moving objects.
Friction, drag forces, air resistance, water resistance
The type of force that occurs when objects like wires, ropes or cables are pulled tightly from both ends.
Tension force
Explain the difference between weight and mass
Weight is a force so it is measured in Newtons. Mass is the amount of “stuff” something is made of. It is measured in kilograms (kg).
A cart is pulled to the right by a force of 15N and to the left by a force of 20N. What is the net force on the cart? in which direction?
The net force on the cart is 5N to the left
Who discovered the law of gravity and three laws of motion?
Sir Isaac Newton
What are two ways to reduce friction?
Make surfaces smoother / Make objects more streamlined / Reduce contact time or amount / Reduce mass / Reduce speed
Is force a vector or scalar quantity?
A vector quantity as it has size AND direction.