<em>The moon doesn’t change shape on its own.</em>
<u>Explanation:</u>
Shapes of moon that we observe is based on the different perspectives of view from the earth and position of moon with respect to the sun. The changes arise due to the rotation of earth on its own axis as well as the revolution of moon on its orbit. The moon doesn’t have any light of its own.
It just reflects off the light from the sun. Due to tidal locking phenomenon one face of the moon permanently faces the sun. Because of the changes in position of moon with respect to the sun the moon is lighted up variably giving rise to various phases like new moon, full moon, crescent etc.
In a uniform circular motion, the magnitude of the speed does not change during the travel and only the instantaneous direction changes.
This speed is always directed along the tangent to the circle at a given point. (refer to the figure attached)
For any circular motion, the must-have acceleration is the centripetal acceleration that is directed towards the centre of the circular locus (if the motion has a tangential acceleration, it has a tangential acceleration additionally).
Therefore, both the directions of the tangential speed and the centripetal acceleration are orthogonal to each other (perpendicular: one is 90 degrees apart from the other).
In mathematics, 2 vectors ( , ) that are perpendicular to each other have a quality that their dot product () equal to zero vector () which is written as .
This quality can be considered when dealing with the velocity vector and the acceleration vector in a manner .
No. Mechanical energy is not conserved. There's quite a bit of friction on the slide. So some of the potential energy is lost to heat on the way down, and the child arrives at the bottom with hot pants and less kinetic energy than you might expect.
,
) that are perpendicular to each other have a quality that their dot product (
) equal to zero vector (
) which is written as
.
.
