An electric motor rotating a workshop grinding wheel at a rate of 176 rev/min is switched off. Assume constant angular deceleration of magnitude 2.71 rad/s^2. Through how many revolutions does the wheel turn before it finally comes to rest?

The number of revolution that the wheel turn before it stops is .

Explanation:

Given:

Initial angular velocity of the motor,

Final angular velocity of the motor,

Value of constant angular deceleration,

Consider that is the time taken by the motor to come to at rest.

The equation of motion of the motor is given by

Substituting the values in equation (1),

Consider the angle of revolution is .

The equation for revolution is given by

Substituting the values in equation (2),

54 degrees incident angle = reflected angle

angle is from normal turned to line of ray

energy stored in the capacitor= 9.72 x 10⁻⁴ j

explanation:

the energy stored in the capacitor is given by

e= 1/2 c v²

e= energy stored

c= capacitance= 1.5 µc= 1.5 x 10⁻⁶f

v= potential difference=36 v

so energy stored= e= 1/2 (1.5 x 10⁻⁶) (36)²

energy stored= 9.72 x 10⁻⁴j