Answer
given,
cooling fan revolution = 850 rev/min
fan turns before revolution = 1500 revolutions


θ = 1500 revolution
θ = 1500 x 2 x π
θ = 9424.78 rad
a) using equation of rotation
ω² = ω₀² + 2 α θ
ω = 0 because body comes to rest
0 = 89² + 2 x α x 9424.78
α = -0.42 rad/s²
b) time take for the fan to stop
ω = ω₀ + α t
0 = 89 - 0.42 t

t = 211.9 s
If you're looking for distance, you have to multiply the time and speed.
0.75 × 45 = 33.75
The rabbit hopped 33.75 m.
green liquid becoming a red liquid
KE= 1/2 mv^2
Kinetic Energy is equal to 1/2 x mass x velocity squared
The mass of the larger ball has TWICE
the kinetic energy. KE is directly proportional to the mass.