There are actually two different kinds of mirrors, and the answer is different for each one.
-- Plain old everyday hand mirror, vanity mirror, bathroom mirror, makeup mirror, etc.
Opaque, reflecting silver coating is on the back of the glass. Light from your tongue or your teeth flows to the front surface of the glass, through the glass, out of the back surface of the glass, bounces off of the silver coating on the back, reverses its direction, enters the back surface of the glass, comes back through the glass again, leaves the front of the glass, goes into your eyes, and you can see your teeth or your tongue.
Both surfaces of the glass, as well as the glass in between the surfaces, are transparent. The silver coating on the back is opaque. I know that, because when I look at the back of a mirror, I can't see any light coming through it. The coating on the back is also reflective ... a big part of the reason why a mirror works.
-- Expensive mirrors used by astronomers and eye-doctors. Known as "first surface" mirrors.
Opaque, reflecting silver coating is on the <em>front</em> of the glass. Light
from your tongue or your teeth flows toward the front surface of the glass,
but never actually gets there. It bounces off of
the silver coating on the front of the glass, reverses its direction, goes into your eyes, and you can see your teeth or
your tongue.
The glass is transparent, but that doesn't matter, because the light never reaches the glass. It only goes as far as the opaque silver coating on the front, and is reflected from there.
Let us first know the given: Tennis ball has a mass of 0.003 kg, Soccer ball has a mass of 0.43 kg. Having the same velocity at 16 m/s. First the equation for momentum is P=MV P=Momentum M=Mass V=Velocity. Now let us have the solution for the momentum of tennis ball. Pt=0.003 x 16 m/s= ( kg-m/s ) I use the subscript "t" for tennis. Momentum of Soccer ball Ps= 0.43 x 13m/s = ( km-m/s). If we going to compare the momentum of both balls, the heavier object will surely have a greater momentum because it has a larger mass, unless otherwise the tennis ball with a lesser mass will have a greater velocity to be equal or greater than the momentum of a soccer ball.
To solve this problem we will apply the concepts related to equilibrium, for this specific case, through the sum of torques.
If the distance in which the 600lb are applied is 6in, we will have to add the unknown Force sum, at a distance of 27in - 6in will be equivalent to that required to move the object. So,
So, Force that must be applied at the long end in order to lift a 600lb object to the short end is 171.42lb