Answer:
gravity
Explanation:
keeps the ball down on the surface
<h2>
Answer:</h2>
<em>Hello, </em>
<h3><u>
QUESTION)</u></h3>
<em>✔ We have: KE = PE (potential energy) </em>
<em>PE = m x g x h </em>
The potential energy that the pebble of mass 1 has is called PE1 and the potential energy that the pebble of mass 2 has is called PE2
PE1 = PE2 ⇔ PE1/PE2 = 1

The mass m1 is therefore 4 times greater than that of the stone of mass m2.
Answer:True
Explanation: The mechanical waves need a medium through which to transport energy because the perturbation travels inside of the medium so it needs molecules that connect elastically the displacement of the wave. For example the sound mainly uses the air molecules to transport the energy also the sound can be traveled in solid materials like metal rods.
A. <span>Standing is health-enhancing because it uses energy.
Because standing can burn a lot of calories.</span>