<u>Note that</u>:
The gravitational potential energy = 
where m: is the mass, g: the acceleration due to the gravity and h is the height from the earth surface
Then, we can increase the gravitational potential energy by increasing the mass or the height from the earth surface
<u>In our question</u>, we can increase the gravitational potential energy by
<u>A) Strap a boulder to the car so that it wights more.</u>
An indicator of average kinetic energy is temperature. Temperature is directly proportional to Kinetic energy of the molecules of an element.
Answer:
rpm
Explanation:
Given that rotational kinetic energy = 
Mass of the fly wheel (m) = 19.7 kg
Radius of the fly wheel (r) = 0.351 m
Moment of inertia (I) = 
Rotational K.E is illustrated as 





Since 1 rpm = 



Answer: Because new theories can come out that better explain observations and experimental results can replace old theories.
Explanation: Theories more than ten years old are usually out of date. Scientists want to prove that the work of other scientists is wrong. New evidence that supports a change prompts scientists to modify earlier theories.