9. what of form of energy is represent by x when electric fan is turned on.
a. heat and light
b. sound and chemical
c. chemical and mechanical
d. mechanical sound of heat

10. what form of energy is contained by margarine batteries and rice
a. light
b. sound
c. electrical
d. chemical

11. what two forms of energy are produced when a cell phone brings and vibrates
a. chemical and sound
b mechanical and sound
c. it and chemical
d. none of these

12. what force prevent our feet from sliding when we run or walk
a. gravity
b. centripetal force
c. friction
d. magnetic force

13. most green plants convert the sun's energy to produce food for humans to do certain works what energy transformation are involved
a.radiant chemical sound
b. chemical light heat
c. solar heat mechanical
d . solar chemical mechanical

14. a dry cell is useless unless it is changed to
a.electrical energy
b. chemical energy
c. nuclear energy
d. potential

16. what is the energy possessed by waterfalls
a. heat energy
b. mechanical energy
c. electrical energy
d. chemical energy

17. when you shout your warning to a friend 50 meters away what carries the sound
a. gas
b solid
c. liquid
d. water
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