Topic 1 - Motion Flashcards
quantity
something we can measure and give a numerical value to
scalar quantity
quantities that have only magnitude (size)
vector quantity
quantities that have magnitude (size) and a direction
acceleration word equation
acceleration (m/s)2 = change in velocity (m/s)
time taken (s)
velocity
the speed of something in a given direction
speed calculation
speed = distance / time
acceleration
a change in velocity
how to work out starting velocity (u)
u = at - v
how to work out final velocity (v)
v = at + u
how to work out distance (x)
x = v squared - u squared / 2a
momentum
a combination of mass and velocity
force
a force that acts towards the centre of the Earth
speed
tells you how far something moves in a certain time
displacement
the distance from start to finish in a straight line; displacement for a journey is usually less than the distance travelled
name some vector quantities
acceleration, displacement, velocity, force, momentum, weight
name some scalar quantities
distance, temperature, time, speed, density, mass, energy
distance equation
distance = average speed x time
time equation
distance / speed
velocity equation
displacement / time
equation for acceleration with distance
acceleration = v squared - u squared / 2 x distance
what are all forces
all vectors (all have magnitude and a direction)
instantaneous speed
speed at a particular point in a journey
how do u measure time in a laboratory when working out the speed
using light gates - its more accurate than using a stopwatch
on a distance/time graph what does a horizontal line mean
the object is stationary
on a distance/time graph what does a straight/sloping line mean
the object is travelling at a constant speed (the sleeper the line, the faster the object is travelling)
how is speed calculated using a distance/time graph
the gradient of the line is the speed
units for acceleration
metres per second squared
acceleration symbol equation
a = v - u
t
a - acceleration
v - final velocity
u - initial velocity
t - time taken for the change in velocity
deceleration
when acceleration causes an object to get slower
what’s the earths force of gravity
9.8m/s2 or 10m/s2
on a velocity/time graph what does a horizontal line mean
the object is travelling at constant velocity
on velocity/time graph, what does a straight/sloping line mean
object is accelerating - the steeper the line the greater the acceleration
on a velocity/time graph what does a a line that is sloping downward mean
it’s decelerating (slowing down)
how do you workout the acceleration from a velocity/time graph
the gradient of a line is the acceleration
what does a negative velocity mean (line below the horizontal axis)
show the object moving in the opposite direction
how to calculate the distance travelled from a velocity/time graph
workout the area of the shape (area under the line)
If an object is moving at constant velocity what is the value of the acceleration?
There is no acceleration
If an object is moving at constant velocity what is the value of the acceleration?
There is no acceleration
