forces Flashcards
What is meant by a vector quantity?
They have a magnitude and a direction
Give 3 examples of vector quantities
Force, velocity, displacement, acceleration etc.
What is meant by scalar quantities?
They have only magnitude, no direction
Give 3 examples of scalar quantities
Mass, speed, distance, temperature etc.
How can we represent vector quantities visually? Explain why this method doesn’t work for scalar quantities.
We can use arrows to represent vectors. The length shows the magnitude and the direction shows the direction of the quantity: This doesn’t work with scalar because they do not have a direction, only a magnitude.
Explain the difference between speed and velocity.
Speed is scalar, and does not take direction into account, but velocity does. They both measure speed but only velocity is a vector.
Define a ‘force’.
An attractive or repulsive interaction between two objects / a push or pull on an object caused by it interacting with something else.
What are the two types of forces? Give examples for each.
Contact: friction, air resistance, normal contact force
Non-contact: gravity, magnetic force, electrostatic force
What is Newton’s 3rd Law?
‘For every action there is an equal and opposite reaction’
Explain Newton’s 3rd Law.
When two objects interact, a force is produced on each object.
What are interaction pairs?
Give an example.
An interaction pair is a pair of forces that are equal and opposite and act on two interacting objects. E.g: the sun and earth, a chair at rest on the ground.
Define gravitational force, and give the two effects of it.
It is the force of attraction between masses.
- On the surface of a planet, it makes all things fall towards the grounds.
- It gives everything a weight
Describe and explain the difference between weight and mass.
Mass is the amount of matter in an object, whilst weight is a measure of the size and gravitational pull on the object. This means that the mass of an object on Earth will be the same as its mass on the Moon, but its weight will change.
Is weight a force?
What is it measured in?
Yes
N
Is mass a force?
No
