Forces Flashcards
properties of scalar quantities
they only have magnitude
NO DIRECTION
properties of vector quantities
have magnitude and an associated direction.
what do arrows represent on vector quantities
The length of the arrow represents the magnitude, and the direction of the arrow shows the direction
what is a force
a push or pull that acts on an object due to the interaction with another object
- have both magnitude and direction, meaning it’s a vector quantity
what are contact forces
forces happening when objects are touching
eg tension or friction
what are non contact forces
forces happening when the objects are separate
examples of contact forces
- friction
- air resistance
- tension
examples of non contact force
- electromagnetic
- magnetic
- gravitational
when does an object experience tension
when it’s being stretched
when does an object experience friction
when it’s sliding past another object
when does an object experience air resistance
when its moving through air
what is weight
the force acting on an object due to gravity
what is Newton’s third law
when two objects interact with each other, they exert equal and opposite forces on each other
The force of gravity close to the Earth is due to what?
due to the gravitational field around the Earth
what does the weight of an object depend on
the gravitational field strength at the point where the object is
equation for weight
mass x gravitational field strength
what is weight measured in
newtons
what is mass measured in
kg
where does the weight of an object act
on the objects centre of mass, which is a single point
what is the relationship between an objects mass and weight
they are directly proportional
how is weight measured
using a newtonmeter
when is work done
when energy is transferred from one store to another
when is work done (forces)
when a force causes an object to move
what happens when work is done against a frictional force
the objects temperature increases
work done equation
W = force x distance
1 joule is equal to…?
1 newtonmetre
what is a resultant force
a single force that has the same effect as all the original forces acting together.
what happens when a car brakes
- the brake presses against the wheel
- friction acts between the brake and the wheel
- the kinetic energy store of the car is transferred to the thermal energy store of the brakes
- the temperature of the brakes increases, and at the same time, the car slows down as it loses kinetic energy
what is displacement
distance in a given direction
what does the mass of an object tell us
how much matter the object has in it
what is gravitational field strength
a measure of the force of gravity in a particular location
what device can we use to determine an objects weight
a calibrated spring balance / newtonmeter
when must the forwards and backwards forces be balanced
when the objects moving at constant velocity
rule when finding work done
the distance must be in the line of action of the force
