SP2 - Forces and Motion Flashcards
Is speed a vector or scalar quantity?
Scalar
What is Newton’s first law of motion?
A moving object will continue to move at the same speed and direction unless an external force acts on it.
A stationary object will remain stationary unless an external force acts on it.
What are balanced forces?
When there is no resultant force, so the velocity won’t change.
What are unbalanced forces?
When there is a resultant force, which will change the speed and/ or the direction of an object.
What is mass?
The quantity of matter there is in an object.
What is weight?
A measure of the pull of gravity on and object.
What are the units of weight?
Newtons
What can be used to measure weight?
A force meter
How does a force meter work?
The spring in the meter stretches as the force on it increases.
What is the gravitational field strength on Earth?
10 N/kg
What is Newton’s second law of motion?
The acceleration depends on:
The size of the force
The mass of the object
What is the formula for force?
Force = mass x acceleration
What is Newton’s third law of motion about?
Forces on two different objects:
When objects touch
At a distance
What are action-reaction forces?
When there is a pair of forces acting on each other.
These forces are the same size and in opposite directions.
What is an example of action-reaction forces?
Playing tug of war with a dog.
