Mechanics Flashcards
Scalar Quantities
Quantities that have only a magnitude and no direction.
Vector Quantities
Quantities that have both a magnitude and direction
SUVAT Equations
v = u +at
s = ut + 1/2at^2
v^2 = u^2 +2as
s = 1/2(u+v)t
SUVAT Equation containing v, u, a, t
v = u +at
SUVAT Equation containing s, u, t, a
s = ut + 1/2at^2
SUVAT Equation containing v, u, a, s
v^2 = u^2 +2as
SUVAT Equation containing s, u, v, t
s = 1/2(u+v)t
Explain the relationship between the horizontal and vertical component
The horizontal and vertical component of the velocity are independent of each other
Velocity definition
Rate Of change of displacement
Speed definition
Rate of change of distance travelled
Acceleration definition
Rate of change of velocity
Newton’s first law
An object will stay at rest or continue to move at a constant speed in the same direction unless acted upon by a resultant force
Newton’s Second law
F = ma
Newton’s Third law
For every action there is an equal and opposite reaction
OR
If object A exerts a force on object B then object B exerts an equal and opposite force on object A
Conditions for newton’s third law pairs
- Same magnitude of force
- Same type of force
- Forces acting in opposite directions
- Forces acting on different objects
GPE Formula
ΔE grav = m g Δh
Kinetic energy formula
E k = 1/2mv^2
Work done equation
Δw = F Δs
Two equations for power
P = W/t
P = Fv
Work done definition
Energy transfer
Power definition
The rate at which work is done
Efficiency definition
A measure of the amount of energy that is transferred into a useful form
Efficiency equation
Efficiency = Useful energy, work done or power output / total input
Moment defintion
The force multiplied by the perpendicular distance of its line of action from the pivot
Moment equation
Moment = force x perpendicular distance from line of action of the force to the pivot
Momentum equation and unit
P = m x v
kgms^-1 or Ns
Principle of conservation of momentum
The momentum before a collision is the same as the momentum after a collision, providing there are no net external forces.
What are elastic collisions?
Where all the kinetic energy is conserved
What is an inelastic collision?
Where not all kinetic energy is conserved.
