A wheel is rotating about an axis that is in the z-direction. The angular velocity w_z is -6.00 rad/s at t=0, increases linearly with time, and is +8.00 rad/s at t =7.00s. We have taken counterclockwise rotation to be positive. a.) Is the angular acceleration during this time interval positive or negative? b.) During what time interval is the speed of the wheel increasing? Decreasing? c.) What is the angular displacement of the whee at t = 7.00s? a.) Angular acceleration is positive because alpha = (delta omega)/ delta t = 2 rad/s^s b.) I'm not sure of how to approach this part. My guess is that the speed is increasing when the rotation is counterclockwise and decreasing when it's clockwise. I need help with this one. c.) I just plugged t=7s into the equation φ(t) = φ_0 + (ω_0)t + (1/2)αt^2 and I got 7.00 rad.