Because of the rule of mask.
This is the same question that I just answered.
Have present the definition of acceleration:
a = Δv / Δt, this is change in velocity per unit of time.
a and v are in bold to mean that they are vectors.
1) a body traveling in a straight line and increasing in speed: CORRECT:
Acceleration is the change in velocity, either magnitude or direction or both. So, a body increasing in speed is accelerated.
2) a body traveling in a straight line and decreasing in speed: CORRECT
A decrease in speed is a change in velocity, so it means acceleration.
3) a body traveling in a straight line at constant speed: FALSE.
That body is not changing either direction or speed so its motion is not accelerated but uniform.
4) a body standing still : FALSE.
That body is not changind either direction or speed.
5) a body traveling at a constant speed and changing direction: CORRECT.
The change in direction means that the body is accelerated. The acceleration due to change in direction is named centripetal acceleration.
The answer is b) force exponerse by charge in electric field
Thank you for posting your question here at brainly. Below is the solution:
Ke up top = 1/2*.25 *225
<span>gain of Pot energy = .25*9.81*1.2 </span>
<span>work input = (1/4)(2 pi *.6)*30 </span>
<span>so </span>
<span>sum of those 3 energies = </span>
<span>(1/2)(.25)v^2</span>
Because no sunlight can penetrate it
