Momentum+and+Energy

=__**Momentum and Energy**__= __**Key Ideas**__ **1. Work and energy are scalar quantities.**

**2. Work is equal to the product of the displacement and the component of the** **force in the direction of the displacement.**

**3 For an object traveling in circular motion, the centripetal force never does work.**

**4. Mechanical energy is the sum of all kinetic and potential energies.**

**5. Work-Energy Theorem: the net work is equal to the change in kinetic energy.**

**6. Conservation of mechanical energy under the action of a dissipative force** **includes the work due to frictional forces (non-conservative forces).**

**7. Power is the time rate of change of work or energy, but it can also be calculated** **using force x speed.**

**8. The impulse is the product of the average force and the time interval through** **which it acts. Impulse is equal to the change in momentum.**

**9. Momentum is conserved in all collision systems. Kinetic energy is conserved** **only in perfectly elastic collisions.**

**10. Objects stick together in perfectly inelastic collisions.**   __<span style="color: #000000; font-family: helvetica,arial,sans-serif;">**Elastic Collisions** __ <span style="color: #000000; font-family: helvetica,arial,sans-serif;">

__**Inelastic Collisions**__

__**2-D Collisions**__