Answer: The elevator must be accelerating.
Explanation:
As the tension force is opposing to the the force of gravity on the load which is hung vertically, and the tension force can adopt any value in order to comply with Newton's 2nd law, if the tension force is less than the force due to gravity, this means that all system is not in equilibrium, so it must be accelerating.
If we assume that the downward is the positive direction, we can write:
mg - T = ma
If T = 0.9 mg, ⇒ mg (1-0.9) =0.1 mg = m a ⇒a = 0.1 g , in downward direction.
Torque = r x F
|F| = mg = 60 * 10 N = 600 N ( assuming g ~ 10m/s^2)
distance of fulcrum = torque / Force = 90/600 m = .15 m.
Her weight = (mass) · (gravity) = (50kg) · (9.8 m/s²)
Work = (weight) · (height) = (50kg) · (9.8 m/s²) · (6 m)
Power = (work) / (time) = (50kg) · (9.8 m/s²) · (6 m) / (15 s)
Power = (50 · 9.8 · 6 / 15) · (kg · m² / s³)
Power = 196 (kg · m / s²) · (m) / s
Power = 196 Newton-meter/second
<em>Power = 196 watts</em>
Answer:

Explanation:
From the question we are told that:
Frictional force 
Coefficient of kinetic friction 
Generally the equation for Normal for is mathematically given by

Therefore

