Mechanics Flashcards
How do you calculate ever age speed?
Speed = distance / time
How do you calculate work done?
Work done = force x distance
What is the SI unit of light intensity?
Candela
What are the differences between scalars and vectors?
A scalar has only magnitude and no direction
A vector has both magnitude and direction
To work out the components of a vector what equations should you use?
A^2 + b^2 = c^2
and
Sohcahtoa
What are the SUVAT EQUATIONS?
S = ut + 1/2At^2 V^2 = u^2 + 2as V = u+at S = ((u+v)/2) x t
What is the force when a car of 9000N is accelerating at 7ms^-2
6422N
In a free body diagram what are the 2 equations you should use initially to work out what is going on?
Sigma F = 0
Sigma F = ma
What equation relates force and velocity
Force = KV^2
Force is proportional to V^2
What is the equation to calculate torque?
Torque = force x perpendicular distance from the pivot
What is the equation to calculate Kinetic Energy?
KE = 1/2mv^2
What equation calculates change in gpe?
/\Gpe = mg/\h
What equation relates gpe and KE?
V = root 2gh
What are the equations to calculate power?
Power = work done / time
Power = force x constant velocity
What is the equation to calculate efficiency?
m = (useful energy out / total energy in) x 100
How do you calculate pressure?
Pressure = force(N) / area
Stress acts like pressure, but within the object.
What is the equation to calculate stress?
Stress = force (N) / cross sectional area (m^2)
What is the equation for the hugs modulus?
E = stress / strain
What is the equation to calculate strain?
Strain = change in length / original length
What is the equation to calculate area
When given length, mass and density?
Area x length = mass / density
What is Newton’s first law?
A body does not change velocity unless acted on by a force.
What is Newton’s second law?
The rate of change of momentum is directly proportional to the resultant force acting on it.
What is Newton’s third law?
Every force has an equal and opposite reaction
