Energy #2. Work & Power

Energy #2. Work & Power

The US and other countries are investing in "renewable resources". The USA is currently at 8% Renewable energy use

Multiple Select

Which of the following are considered "renewable" energy sources?

• Wind & Solar

• Natural Gas & Petroleum

• Biomass

• Coal

• Hydropower & Geothermal

Solar Power in the USA

• Has limitations due to climate

• Cost has dropped to $0.06 /kilowatthour

• Solar panels have a life expectancy of 25-30 years

• Cost to purchase panels - $15-25,000

Wind Energy

• Predominantly found in the central and northern USA

• Average cost is $0.07 /kilowatthour

• Costly to build and maintain

• Wind farms are most cost effective

Poll

Which do you think is a better "green energy" choice in Ohio based on our location and climate?

• Solar Panels

• Wind Farm

Multiple Choice

Which renewable energy uses thermal heat from the ground?

• Solar

• Wind

• Hydrothermal

• Geothermal

Tidal Energy

Tidal energy is being evaluated as well but has significant disadvantages.

Poll

If you lived on the coast, would you want to look at a floating tidal power field?

• Yes

• No

Multiple Choice

Energy is the ability to do work.

Work = Force * Distance moved

If a person pushes against a rock with a force of 25 Newtons. The rock does not move. How much work is done?

• 0 Joules

• 25 Joules

Multiple Choice

If nothing is touching an object that is moving-- is work being done?

• Yes

• No

Multiple Select

Amy uses 20N of force to push a lawn mower 10 meters. How much work does she do?

• 200 J

• 200 N*m

• 2 J

• 2 N*m

Multiple Choice

A force of 6 Newtons was applied and 72 Joules of Work were done on an object. How far was the object moved? (W=F*D)

• 12 J

• 12 m

• 432 J

Multiple Choice

136 Joules of Work were done on an object that moved 27.2 meters. How much force was applied to the object?

• 3699 J

• 5 N

• no work was done

Multiple Select

Power = Work / time

How much power is done If 100 Joules of work to move an object required 5 seconds

• 20 N

• 20 J/s

• 20 W

• 500 W