Kinetic Energy
Work Done
Work done and energy transferred are measured in Joules, J.
Is is when a force moves something.
W= F * d
Work done = Force * Distance
J - Joules N -Newtons m - metres
Power
How quickly work is being done
P = E / t
Power = work done / time
W -Watt J -Joules s -Seconds
Gravitational Potential Energy
Force of gravity pulling on us.
Ep = m * g * h
Gravitational potential energy = mass * gravitational field strength * height
J- Joules kg- Kilograms N/kg-Newtons per kilogram m- metres
Kinetic energy
Energy a moving object has
Ek = 0.5 * m * v^2
Kinetic energy = 0.5 * mass * speed^2
J- Joules kg- Kilogram m/s metres per second
Pendulum
Transfers gravitational potential to kinetic energy and back.
At highest point, no kinetic energy but maximum gravitational potential energy.
Gravitational potential energy transfers to kinetic energy as it swings down and it accelerates.
As it swings upwards kinetic energy is transferred to gravitational potential energy and decelerates
Energy is also transferred as heat to the surroundings so each swing is weaker.
Momentum
Momentum is the tendency of the object to keep moving in the same direction.
p = m * v
Momentum (kg m/s) = Mass (kg) * velocity (m/s)
Momentum also depend on the direction of travel.
it can change if the object change speed or change direction.
If there are no other external forces acting on the object, the total momentum stays the same in collisions and explosions.
Momentum is conserved
Always write momentum before = momentum after in a calculation.
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