Motion
Velocity
How fast something is moving measured in m/s
Newtons
Units of force
Force
A push/pull
m2
Units for measuring area
Joules
Units for energy
Joules
Units for work
V = d/t
Velocity = distance / time
Acceleration
Change in speed caused by unbalanced forces measured in m/s2
Amount of matter that makes up an object measured in Kg
Net force
Resultant force left over once opposing forces have been cancelled out
Pa or N/Kg
The two units used for pressure
Ek
Kinetic energy - the type of energy that moving objects have
Work
A gain or loss of energy due to a force acting on an object over a distance
P = W/t
Power = Work/time
Constant Speed
No change in velocity, straight line on a d/t graph, flat line on a V/t graph, caused by balanced forces
Weight
Force acting downwards on an object due to the interaction of gravity on its mass measured in Newtons
F=ma
Equation for calculating net force - depends on mass and acceleration
F=mg
Equation for calculating weight force in Newtons
Ep
Gravitational potential energy, objects store this when they are place somewhere high
J/s or Watts
The two units for Power
g = 10N/Kg or 10m/s2
strength of gravity on Earth
Deceleration
Decrease in speed measured in m/s2 caused by net force opposing direction of motion
Friction
A force that opposes motion/acts against motion due to a rough surface or high surface area
Unbalanced forces
When net force is greater than 0N this causes an object to accelerate
P=F/A
Equation for calculating pressure, force must be in Newtons and area must be in m2
Conservation of Energy
Energy is never created or destroyed it gets transformed from one type of energy to another
Power
Ek = 1/2 m V2
Kinetic energy = half x mass x Velocity squared
Terminal Velocity
When a falling object falls at constant speed due to balanced forces (air resistance = weight force)
Air resistance
A kind of friction that pushes against falling objects that increases as the object speeds up - more particles of air hit the object per second as it falls faster
Balanced Forces
When net force = 0N because the opposing forces are equal and opposite so cancel out. This causes an object to stay in constant motion or stay stationary
Decreases pressure
Increasing surface area and/or decreasing force
Ep=Ek
Assumption used to calculate the speed of a falling object at the end of its fall
Increases power
More work done over a shorter time
W = Fd
Work = Force x distance