If the block is sliding at constant velocity then its speed is constant. That means it is not losing any kinetic energy. There is no friction acting and the coefficient of kinetic friction is zero. Sadly, that choice of answer is not offered.
Answer:
Explanation:
From the question, we were made to understand that the collision between the two billiard balls was an elastic collision. Hence, an elastic collision is one in which the kinetic energy is conserved. Meaning the kinetic energy before the collision is still retained after the collision.
Kinetic energy before collision = kinetic energy after collision
1/2mv^2 = 1/2mv^2
There was no gain nor loss in energy
It will reflect because polished metal is like glass or water it’s shiny and smooth
Answer:

Explanation:
We have,
Mass of Mars is, 
Mass of its moon Phobos, 
Distance between Mars and Phobos, d = 9378 km
It is required to find the gravitational force between Mars and Phobos. The force between two masses is given by

Plugging all values, we get :

So, the gravitational force is
.
Answer:
x is vertical and y is horizontal
Explanation: