An empty 240 kg elevator accelerates upward at 1.4 m/s^2. The acceleration of gravity is 9.8 m/s^2.What is the tension in the cable that lifts the elevator cab? Answer in units of N.
Tension in the cable is equal to the force due to action of acceleration due to gravity plus the force for accelerating the elevator further by 1.4 m/s.
Thus tension in cable =
(Mass of elevator)*(accelaration due to gravity + upward accelaeartion of elevator)
= 240*(9.8 + 1.4) = 240*11.2 = 2688 N
Answer: Tension in cable is 2688 N