I think the correct answer would be that because electromagnets are powerful and can be turned off and on anytime. Electromagnet is a magnet in which the magnetic field is made by the electric current that is induced to the system.
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:
20,850 N
Explanation:
We can solve the problem by using second Newton's Law:

where
F is the force
m is the mass
a is the acceleration
In this problem, we have:
m = 70 kg is the mass
is the acceleration (which is negative, because it is a deceleration)
So, we can use the equation above to find the force:

and the negative sign simply means that the force is in the opposite direction to the motion.
Answer:
height of a cliff is 45.86 m
Explanation:
u=8 m/s
t=2.35 s
the height of the cliff is
