Which of the following is not true of the seasons?

a. the earth is closer to the sun during the summer and farther away from the sun during the winter.
b. the seasons are caused the tilt of the earth on its axis.
c. summer does not start on the same day in every country on the earth.
d. during the summer, days are longer.

Amachinist turns the power on to a grinding wheel, at rest, at time t = 0 s. the wheel accelerates uniformly for 10 s and reaches the operating angular velocity of 96 rad/s. the wheel is run at that angular velocity for 40 s and then power is shut off. the wheel slows down uniformly at 1.5 rad/s2 until the wheel stops. in this situation, the time interval of deceleration is closest to: