Gravity increased the downward speed (or decreases the upward speed) by 9.8 m/s every second.
21.2/9.8 = 2.2 seconds
Models help us to understand systems and their properties
The axis of the Earth's rotation is tilted relative to the plain of the Earth's revolution around the Sun.
The question is worded very poorly, but you'd have to say it's TRUE.
Answer:

Explanation:
Initial angular speed of the ferris wheel is given as



final angular speed after friction is given as



now angular acceleration is given as



now torque due to friction on the wheel is given as



Now the power required to rotate it with initial given speed is

