motion and pressure (IMPORTANT!) Flashcards
acceleration
The amount by which speed increases in one second.
atmospheric pressure
the pressure acting on us from the air around us.
average speed
The total distance travelled in the total time taken for a complete journey.
centre of gravity
The point in an object where the force of gravity seems to act.
centre of mass
The point in an object where the mass of an object seems to act.
compressed
Squashed into a smaller space.
density
The mass of a material in a certain volume.
distance-time graph
A graph that shows how far an object moves each second.
gas pressure
The force produced by air particles when they collide with a surface.
incompressible
Cannot be compressed (squashed)
instantaneous speed
The speed at a particular moment.
law of moments
An object is in equilibrium if the clockwise moments equal the anticlockwise moments.
liquid pressure
The pressure produced by collisions of particles in a liquid.
metres per second
A unit of speed
moment
A measure of the ability of a force to rotate an object on a pivot.
newton metres
The unit of moment
newtons per metre squared
A unit of pressure
pivot
The point of balance (e.g in a lever or seesaw)
pressure
A force exerted on a certain area.
relative motion
The difference between the speeds of two objects.
speed
A measure of how far something travels in a given time
equation for speed
speed = distance(m)/ time (s)
equation for pressure
pressure = force (N) / area (m^2)
equation for moments
moment (Nm) = force (N) × perpendicular distance
from the pivot (m)
