Answer:
a option okkkkkkkkkkkkkk
Answer:
particles are free to move
Which of the following could be used to convert chemical energy to heat energy?
a. a chair sitting still
c. a leaf absorbing sunlight
b. a battery powering a flashlight d. a rock hitting the ground
Answer:
C
Explanation:
Inside a battery there are chemical reactions. When the battery is powering a flashlight, this chemical energy gives a heat one.
A certain light bulb consumes 200J of electrical energy per second, but only emits 25J of light energy per second. Calculate the efficiency of this bulb.
Answer:
The answer is 12.5%
Explanation:
The efficiency of a light bulb is:
Light energy comes out of the bulb / Electrical energy that was put in
= 25J / 200J = 12.5%