Answer:
The precise point is that gravitational energy is potential energy unless it makes something move, and then the energy is converted to kinetic energy, no work can be done. So a big rock at the top of a hill has no kinetic energy. Its only when it rolls down that work is done, and this can be converted to useful energy.
Explanation:
<span>c) two or more waves overlap and combine</span>
Force is a vector quantity & must<span> be treated accordingly; the </span>electric force between two<span> objects always acts along the line that connects their centers of </span>charge<span> ... </span>Electric forces can<span> be </span>either attractive<span> or</span>repulsive<span>, but </span>gravitational forces<span> are always </span>attractive<span> (because objects </span>can<span> have </span>either<span> a positive or a negative </span>charge<span>, .</span>
Answer: 80mph
Explanation:
Since the two cars are approaching each other, it can be said that:
Speed of Car A moving from left to right = 30mph
Speed of Car B moving from right to left = 50mph
Now recall that relative speed of objects moving in opposite directions is equal to the sum of each speed
Hence, Relative speed = (Speed of Car A + Speed of Car B)
Relative speed = (30mph + 50mph)
Relative speed = 80mph
