The mass of a lift is 2000 kg. When the tension in the supporting cable is 28000 N, its acceleration is

(a) 30 ms-2 downwards                                       (b) 4 ms-2 upwards

(c) 4 ms-2 downwards                                         (d) 14 ms-2 upwards

Concept Videos :-

#1-Forces & Types
#2-Common-Forces-in-Mechanics-Normal-Reaction
#3-Common-Forces-in-Mechanics-Tension

Concept Questions :-

Types of forces

Key Idea         Apparent weight > actual weight, then the lift is accelerating upward.

Here, lift is accelerating upward at the rate of a 

                                                        

Hence, equation of motion is written as 

               R-mg=ma

28000-20000     =2000aa=80002000= 4 ms-2  upwards

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