So much brighter and the moon would be so much darker than it is now because the moon is further away from the moon than it is now...
1) At the moment of being at the top, the piston will not only tend to push the penny up but will also descend at a faster rate at which the penny can reach in 'free fall', in that short distance. Therefore, at the highest point, the penny will lose contact with the piston. Therefore the correct answer is C.
2) To solve this problem we will apply the equations related to the simple harmonic movement, hence we have that the acceleration can be defined as

Where,
a = Acceleration
A = Amplitude
= Angular velocity
From a reference system in which the downward acceleration is negative due to the force of gravity we will have to



From the definition of frequency and angular velocity we have to




Therefore the maximum frequency for which the penny just barely remains in place for the full cycle is 2.5Hz
<u>Answer:</u>
The spinning of the earth around its own axis causes day and night.
<u>Explanation:</u>
Earth has two types of motions. It spins around its own axis causing day and night every 12 hours and completes a rotation in 23.93 hours that make a full day. The part of the earth that faces sunlight during spinning experiences day and the other part has night. It also rotates around the sun and completes one rotation in 365 days that makes a year.