Hi there!
Use the following equation: (Newton's Second Law)
∑F = ma, where:
∑F = net force (J)
m = mass (kg)
a = acceleration (m/s²)
Plug in the given values:
∑F = 1500 · 40 = <em>60,000 J</em>
From what I have been told, the four basic forces regarding physics are the strong or powerful force, a gravitational force, an electromagnetic force, and a weak force. The strong force binds nuclei. Weak forces take care of nuclear decay. Electromagnetic forces exists when two or more objects have an electric charge like a magnet or positive and negative, negative and positive And gravitational forces is just gravity. What holds us down.
Answer: I'm not sure, but I think it would be a <em>total lunar eclipse </em>
By Newton's second law, the net vertical force acting on the object is 0, so that
<em>n</em> - <em>w</em> = 0
where <em>n</em> = magnitude of the normal force of the surface pushing up on the object, and <em>w</em> = weight of the object. Hence <em>n</em> = <em>w</em> = <em>mg</em> = 196 N, where <em>m</em> = 20 kg and <em>g</em> = 9.80 m/s².
The force of static friction exerts up to 80 N on the object, since that's the minimum required force needed to get it moving, which means the coefficient of <u>static</u> friction <em>µ</em> is such that
80 N = <em>µ</em> (196 N) → <em>µ</em> = (80 N)/(196 N) ≈ 0.408
Moving at constant speed, there is a kinetic friction force of 40 N opposing the object's motion, so that the coefficient of <u>kinetic</u> friction <em>ν</em> is
40 N = <em>ν</em> (196 N) → <em>ν</em> = (40 N)/(196 N) ≈ 0.204
And so the closest answer is C.
(Note: <em>µ</em> and <em>ν</em> are the Greek letters mu and nu)