Answer:

Step-by-step explanation:
given,
angular deceleration, α = -0.5 rad/s²
final angular velocity,ω_f = 0 rad/s
angular position, θ = 6.1 rad
angular position at 3.9 s = ?
now, Calculating the initial angular speed




now, angular position calculation at t=3.9 s



Hence, the angular position of the wheel after 3.9 s is equal to 5.83 rad.
Answer:
Step-by-step explanation:
t=45min
d=4km
45min/60min = 0.75 hours
v=d/t
v=4km/0.75hours
v=5.33km/hour. So the answer is B. 45 minutes.