Mechanical advantage is the ratio of output force to input force of a machine.
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<span>If the refrigerator weights 1365 and you are not exerting any vertical force on it, then the normal force is also 1365N. so Fn=1365
Fsf = Static frictional force = (coefficient of static friction) * (Normal force)
So the least for you could exert to move it is equal to the Fsf.
Fsf = (0.49)(1365N)</span><span>
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The initial height of the first body is given by:

where
g is the gravitational acceleration
t is the time it takes for the body to reach the ground
Substituting t=1 s, we find

The second body takes takes t=2 s to reach the ground, so it was located at an initial height of

The second body started its fall 1 second before the first body, therefore when the second body started its fall, the first body was located at its initial height, i.e. at 4.9 m from the ground.