P8,P9 Flashcards
What is a scalar quantity?
- A quantity that only has a magnitude
- A quantity that isn’t direction dependent
What is a vector quantity?
A quantity that has both a magnitude and an associated direction
Examples of vector quantities
Force
Velocity
Acceleration
Displacement
Momentum
Examples of scalar quantity
Speed
Distance
Mass
Temperature
Time
How can a vector quantity be drawn and what does it show?
As an arrow
- The length of the arrow represents the magnitude
- The arrow points in the direction of the quantity
What is a force?
A push or pull on an object due to an interaction with another object
What are 2 categories that all forces can be split into?
- Contact forces
- Non contact forces
Examples of contact forces
- Air resistance
- Friction
- Tension
Examples of non-contact forces
- Gravitational forces
- Magnetic forces
- Electrostatic forces
What is weight?
The force that acts on an object due to gravity and the object’s mass
What is an interaction pair?
A pair of forces that are equal and opposite and act on two interacting objects
- Sun and Earth
What is magnitude?
Magnitude refers to the size of a numerical value
What is a physical quantity?
Something that can be measured
What is the unit used for weight?
Newton (N)
What quantities does weight depend on?
- The object’s mass
- Strength of the gravitational field at the location of the object
What is mass?
A measure of how much matter there is in an object
What quantity of an object changes depending on its location?
Weight, a 1kg mass will weigh 1.6N on the Moon but on Earth the same 1kg mass will weigh 9.8N.
What is meant by an object’s centre of mass?
The point representing the mean position of the matter in a body
What piece of equipment can be used to measure an object’s weight?
A calibrated spring-balance or newton-meter
The weight of an object and the mass of an object are said to be ____
Directly proportional
This means that if you double the mass of an object, the weight doubles too
What is the resultant force?
The overall force on an object
What is the name given to the single force that is equivalent to all the other forces acting on a given object?
The resultant force
What happens when a force moves an object through a distance?
Energy is transferred and work is done on the object
What happens when work is done against frictional forces?
- A rise in temperature of the object occurs
- Kinetic energy is converted to heat
Why does air resistance slow down a projectile?
It acts just like friction does working against the object. Kinetic energy is converted into heat, slowing down the object
What is it called when the forces acting on an object combine to give a resultant force of zero?
Equilibrium
What are the 3 things that can happen when a force is applied to a object?
- Stretch
- Bend
- Compress
Explain the relationship between the force applied and the extension of an elastic object
The extension is directly proportional to the force applied, provided that the limit of proportionality is not exceeded
What are the 2 types of change in shape or deformation?
- Elastic
- Plastic