Solid at room temperature
It gets attracted due to electro magnetizing
If the surface is rough then the average force needed to move the wooden block will be more as the friction between the surfaces will be more.
Hence, the least force will be required on the smoothest surface and the greatest force will be required for the roughest surface.
a) Hence, the order will be: B > D > A > C
b) When the surface is glued then the force of friction will increase. Hence, it will require more force to move the wooden block on the surface. Hence, the more required will be more than 105 N.
True, because water balance is the balance between intake and output
Answer:60 rev/min
Explanation:
Given
angular speed of first shaft 
Moment of inertia of second shaft is seven times times the rotational speed of the first i.e. If I is the moment of inertia of first wheel so moment of inertia of second is 7 I
As there is no external torque therefore angular momentum is conserved
