9.02: Potential Energy and Energy Conversions

What is the principle of conservation of energy?

• energy cannot be created or destroyed but can only be converted from one form to another

• energy can be created and destroyed as it converts from one form to another

• energy cannot be converted from one form to another

What is the energy conversion when you burn wood for a fire?

• electrical to heat and light

• light to kinetic and heat

• chemical to heat and light

• chemical to electrical and heat

What is the energy conversion when you put batteries in a flashlight to make it turn on?

• chemical to light

• light to kinetic

• chemical to heat

• nuclear to light

What is the energy conversion when a wind turbine turns to provide energy to a power grid?

• electrical to potential

• potential to kinetic

• kinetic to electrical

• nuclear to heat

What is the energy conversion when you feel the warmth of the sun?

• nuclear to heat

• nuclear to kinetic

• potential to nuclear

• light to nuclear

What is the energy conversion when photosynthesis takes place as the sun makes a plant grow?

• electrical to chemical

• potential to nuclear

• chemical to potential

• light to chemical

What is the definition of potential energy?

• The energy an object has due to its position in a force field

• The energy an object has due to its motion

• The energy an object has due to its chemical composition

• The energy an object has due to its mass

What is the formula for the gravitational potential energy  $\left(E_g\right)$  of an object of mass  $\left(m\right)$  held at a height  $\left(h\right)$  above the ground?

•  $E_g\ =\ mgh$  

•  $E_g=\frac{1}{2}mgh^2$  

•  $E_g\ =\ 2mgh^2$  

•  $E_g=\ \frac{mg}{h}$  

What are the units of gravitational potential energy?

• Joules

• Watts

• Metres

• Ohms

Who was the first person to be credited with discovering that energy is conserved?

• James Joule

• Robert Mayer

• Robert Pattison

• James Young