Mechanics Flashcards
Equation for work done?
work done = force x distance
where force is constant
where distance is one, same direction
What are forces that promote motion called?
propulsive
When is SUVAT used in further maths?
only when time is an important element
Equation for kinetic energy?
0.5mv^2
squaring of the speed is why we do not have to be concerned about the direction
What is the Work Energy Principle?
TOTAL work done =
0.5mv^2 - 0.5mu^2
What is equal to the work done by a force?
work done by a force on an object is equal to the increase in its kinetic energy
Work done(propulsively) - Work done (repulsively)
equation for Gravitational Potential Energy?
GPE = mgh
State the law of Conservation of Mechanical Energy.
if the ONLY force acting on an object or system of objects is weights, then mechanical energy is conserved.
GPE + KE= mgh + 0.5mv^2 = constant
what is the equation for average power?
average power =
(work done/time taken)
what is the equation for power?
power = force x speed
what is unique if there is no change in KE?
if the change in KE=0, total work done=0;
so tractive force=resistive force
