A wheel is rotating about an axis that is in the $z-$direction. The angular velocity ${}_z$ is $-6\mathrm{.}00ra\frac{d}{s}$ at $t=0,$ increases linearly with time, and is $+4\mathrm{.}00ra\frac{d}{s}$ at $t=10\mathrm{.}0s.$ We have taken counterclockwise rotation to be positive.

Part A

Is the angular acceleration during this time interval positive or negative?

positive

negative

Request Answer

Part B

How long is the time interval during which the speed of the wheel is increasing?

Express your answer with the appropriate units.

$t_1=,||$

Part C

How long is the time interval during which the speed of the wheel is decreasing?

Express your answer with the appropriate units.

$t_2=$

Part D

What is the angular displacement of the wheel from $t=0s$ to $t=10\mathrm{.}0s?$ Express your answer in radians.

$=[,]rad$