Unit 1 Flashcards
what is speed
the distance traveled per unit time( speed = distance/time)
what is acceleration
when the speed is changing(Change in velocity over time)
what is velocity
speed in a given direction
what is mass
the amount of matter in an object
what is weight
it is a gravitational force measured in newtons
how do you calculate weight
mass x gravitational field strength
what will the effect be in the same object on different planets
mass will be the same but weight will be different
what is density
mass/unit volume
how do you find the density of a liquid
by measuring the mass of a measuring cylinder, adding the liquid and measuring the mass again
The mass of the liquid can then be found along with density
how to find the density of irregular shaped object
by placing it in water and measuring the volume before and after
what is the density of water
1 g/cm^3
what happens if the density of the object is greater or less than the density of water
if greater, it will sink
if lesser, it will float
What is newtons first law
states that an object has constant velocity unless acted on by a resultant force
what is newtons second law
force x mass = acceleration (f=ma)
what is newtons third law
every action force has an equal and opposite reaction
what is terminal velocity
the maximum velocity reached in free fall
how does terminal velocity get reached
as objects accelerate , air resistance increases
This causes resultant force downwards to decrease
acceleration starts to decrease
there is then equal and opposite reaction so there is no resultant force
terminal velocity is reached
What is friction
the force between two surfaces which impedes motion and results in heating
features of an object moving in a circle
speed is constant but direction is always changing
means velocity is always changing
it is therefore accelerating and there must be a force perpendicular to its velocity towards the centre of the circle