LEARNING TARGET: I will be able to use The Law of Conservation of Energy to solve motion problems that include energy gained/lost during today's class

WORDS O' THE DAY:

• Work: A transfer or change of Energy
• Gravitational Potential Energy: Energy based on altitude
• Kinetic Energy: Energy of motion based on mass & velocity
• Mechanical Energy = The sum of all potential and kinetic energy in a system
• friction = Heat energy is generated when a moving object transfers some of its energy to individual molecules (such as air)

CALENDAR:

Work, Power & Energy Test on FRIDAY, March 10th.

FORUMULAE OBJECTUS:

• U_g = mgh
• KE = 1/2mv²
• TME = U + KE
• W = Fd = Fdcosθ = ∆E
• ∆E = 0
• ∆KE + ∆Ug = 0 (when friction is absent)
• ∆E = +/- W (when energy is lost or gained)
• ∆KE + ∆Ug = +/- W (when energy is lost or gained)
• Power = Energy/time
• Power = Fv

WORK O' THE DAY:

Opener:

Let's recollect yesterday power problem:

Let's say you are driving a 1450 kg car that is moving at 55 mph. You hit the brakes and your car stops in a fairly comfy 10. seconds.

How much power did you brakes exert on the wheels of your car?

Now please determine how much force is exerted during that time

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Imagine that you have a 4500 Watt generator hooked up to a winch. How far would it move a 2500 kg car in 10. sec?

Now for the A+ review question:

Imagine you have a block (mass = m) on top of a ramp of height (h) and length (l) and angle to the horizontal (θ) with a coefficient of friction of μ.

The block slides down the ramp losing energy to friction as it goes.

The block his some sort of bumper at the bottom of the ramp (losing no energy in the process) and begins sliding back up the ramp.

Work with your team to create a method for solving for the final height the block achieves (not how far up the ramp)