Answer:
They will move the fridge if they all push in the same direction, but it will not move with constant velocity
Explanation:
The maximum static friction force is
(negative sign since its direction is opposite to the push applied by the people)
Sam can apply a force of 130 N, while Amir and Andre can apply a push of 65 N each, so the total force that they can apply, if they push in the same direction, will be:

This force is larger than the frictional force, so the fridge will start moving.
However, the net force on the fridge will be:

And according to Newton's second law,

where m is the mass of the fridge and a its acceleration, since the net force is not zero, then the fridge will have a non-zero acceleration, so it will not move with constant velocity.
Answer:
Δu=1300kJ/kg
Explanation:
Energy at the initial state

Is saturated vapor at initial pressure we have

Process 2-3 is a constant volume process

The overall in internal energy
Δu=u₁-u₃
We replace the values in equation
Δu=u₁-u₃

Δu=1300kJ/kg
Answer:

Explanation:
Average speed is given by
where
is total distance and
is time.
Plugging in given values, we get:
.