S4 - Physics Test (3) Flashcards
What are the 2 types of quantities in physics?
Scalar & Vector
What is the definition of ‘Scalar’?
A quantity that has magnitude only
What is the definition of ‘Vector’?
A quantity has both magnitude and direction
What are examples of scalar quantities?
- Distance
- Speed
- Time
- Energy
- Temp.
- Mass
What are examples of vector quantities?
- Displacement
- Velocity
- Acceleration
- Force
What is the definition of acceleration?
The rate at which the speed of an object changes over time
What 2 things does acceleration depend on?
- How much the speed changes
- How much time the change in speed takes
What does it mean when an object is at rest?
It’s speed is 0m/s
When will acceleration have a negative answer?
When an object is slowing down (decelerating)
What is acceleration measured in
m/s/s
What are forces measured in?
Newtons (N)
What 3 things can force do to an object?
Change its: speed/shape/direction
What are the 2 types of forces?
Contact and non-contact
What is a contact force?
A force that has to touch the object to affect it
What is a non-contact force?
A force that does not have to touch the object to affect it
Name the types of contact forces?
Push, pull, friction, tension & spring force
Name the types of non-contact forces?
Gravity & magnetism
What is friction and what direction does it act in to an object?
An opposing force, acts in the opposite direction of motion
What direction does weight always act in?
Down
What is weight and what is it measured in?
A measure of gravity’s pull on an object (a force) newtons (N)
What is mass and what is it measured in?
A measure of how much ‘stuff’ an object is made up of, Kg
What does newton’s third law talk about?
How every action (object) has an equal but opposite reaction (force)
What does newton’s first law talk about?
Balanced forces - when 2 or more forces acting on an object are equal in size but opposite in direction
What does newtons second law talk about?
Unbalanced forces - when 2 or more forces acting on an object are not equal in size or are not opposite in direction
