Physics Y10 Forces 1 Flashcards
are forces vector or scalar quantities
vector
how do you represent forces in a diagram
arrows where the width represents the magnitude and the direction represents the direction
calculate resultant force
(sum of forces in one direction) - (sum of forces in the opposite direction)
what is Newton’s first law
- a body at rest will stay at rest unless acted on by a resultant force
- a body in motion will remain in that motion unless acted on by a resultant force
what is Newton’s third law
for every action force, there is an equal and opposite reaction force
what is mass + units
the measure of how much matter there is in an object (kilograms, kg)
when does mass change
only if the object changes
are mass and weight vector or scalar
mass - vector
weight - scalar
what is weight + units
a measure of how much force the pull of gravity has on an object (Newtons, N)
when does weight change
when mass or gravitational field strength changes
calculate weight
mass * gravitational field strength
gravitational field strength unit
Newtons per kilogram, N/kg
what is the gravitational field strength on Earth
~9.8N/kg
what is Newton’s second law
force = mass * acceleration
what is the law of conservation of energy
energy cannot be created or destroyed, only transferred
what is work done
the energy transferred when something is moved
calculate work done + units
work done (Joules, J) = force * distance in direction of force
what are the energy stores
- elastic potential
- kinetic
- gravitational potential
- chemical
- electrostatic
- magnetic
- thermal
- nuclear
what are the energy transfers
- mechanical work
- electrical work
- heating
- radiation
