Answer:
Explanation:
Newton's first law of motion:
An object in motion stays in motion, and an object at rest stays at rest, until acted upon by an unbalanced force.
Newton's second law:
The net force on an object is equal to its mass times its acceleration.
Newton's third law:
For every action, there is an opposite and equal reaction.
The correct answer that would best complete the given statement above would be the second option. A screw is an inclined plane wrapped around a cylinder. <span>The efficiency of a screw is low because there is more input than output. In other words, it is because of friction. Hope this answer helps.</span>
348.34 m/s. When Superman reaches the train, his final velocity will be 348.34 m/s.
To solve this problem, we are going to use the kinematics equations for constant aceleration. The key for this problem are the equations 
and 
where 
is distance, 
is the initial velocity, 
is the final velocity, 
is time, and 
is aceleration.
Superman's initial velocity is 
, and he will have to cover a distance d = 850m in a time t = 4.22s. Since we know , and , we have to find the aceleration in order to find .
From the equation we have to clear , getting the equation as follows: 
.
Substituting the values:
To find we use the equation .
Substituting the values:
The solution you should use is Hooke's law: F=-kx
It should have the same signs because they repel due to the stretch of the spring.
a. Since there is a constant energy within the spring, then Hooke's law will determine the possible algebraic signs. The solution should be
<span>F = kx
270 N/m x 0.38 m = 102.6 N
</span>
b. Then use Coulomb's law; F=kq1q2/r^2 to find the charges produced in the force.
