At t=0 a grinding wheel has an angular velocity of 25.0 rad/s. It has a constant angular acceleration of 31.0 rad/s2 until a circuit breaker trips at time t = 1.80 s. From then on, it turns through an angle 432 rad as it coasts to a stop at constant angular acceleration.(a) Through what total angle did the wheel turn between t = 0 and the time it stopped? (b) At what time did it stop? (c) What was its acceleration as it slowed down?

a) , b) , c)

Explanation:

a) The travelled angular position during acceleration is:

The travelled angular position during deceleration is:

The total travelled angular position is:

b) The final angular speed at acceleration phase is:

The angular deceleration experimented by the grinding wheel is:

The period of time of the deceleration phase is:

The instant when the grinding wheel stops is:

c) The angular deceleration is:

a small object of mass 3.66 g and charge -17.6 µc is suspended motionless above the ground when immersed in a uniform electric field perpendicular to the ground. what are the magnitude and direction of the electric field?