Electrical to mechanical

Chemical to electrical

Mechanical to electrical

Chemical to mechanical

Some of the chemical energy in the natural gas transforms into thermal energy, which heats the water. Then some of the thermal energy changes into sound energy when the water forms steam and the steam leaves the kettle.

Some of the thermal energy in the natural gas transforms into sound energy when the water becomes hot. Then some of the sound energy changes into light energy when the kettle becomes warm.

Some of the electrical energy in the natural gas transforms into thermal energy, which causes the water to form steam. Then some of the thermal energy changes into sound energy and light energy when the steam leaves the kettle.

Some of the light energy in the natural gas transforms into chemical energy in the water. Then some of the chemical energy changes into kinetic energy when steam leaves the kettle and into sound energy when the water boils.

1 and 2

2 and 3

3 and 4

6 and 7

point A

point B

point C

point D

When the rider is at the top of the hill, her potential energy is the greatest, and her kinetic energy is the least.

As the rider moves up the hill, her kinetic energy increases, and her potential energy decreases.

When the rider goes down the hill, her potential energy increases, and her kinetic energy decreases.

As the rider reaches the bottom of the hill, her kinetic energy and her potential energy decrease.