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29 votes
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A body of mass 2kg is suspended from the ceiling of a lift with a light inextensible string. If the lift moves upwards with acceleration of 2ms-2, what is the magnitude of the tension in the string (g = 1Oms-2)?​

User IRaS
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1 Answer

10 votes
10 votes

Answer:

24 N

Step-by-step explanation:

The force on the body due to gravity is ...

F = mg = (2 kg)(10 m/s²) = 20 N

in the downward direction.

The net force on the body required to accelerate it upward at 2 m/s² is ...

F = ma = (2 kg)(2 m/s²) = 4 N

The tension in the string must be enough to overcome the force due to gravity and provide a net force upward.

-20 N + T = 4 N

T = 24 N

The tension in the string is 24 newtons.

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Additional comment

Here, "m" is used to represent both mass and meters. In the force formula, it is mass. In the units for acceleration, it is meters.

User Arturs
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