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A man of mass 60 kg, is riding in a lift. The weights of the man, when the lift is accelerating upwards or downwards at 2ms^{-2} are respectively:

  • Option 1)

    720 N and 480 N

  • Option 2)

    480 N and 720 N

  • Option 3)

    600 N and 600 N

  • Option 4)

    None of these

 

Answers (1)

best_answer

 

Lift accelerating down with 'a' -

V= variable

a<g

mg-R=ma

R=m(g-a)

- wherein

Apparent weight  <  Actual weight

 

 

Lift is accelerating Upward with acceleration = a -

v=variable,


a< g


R-mg=ma

R=m(g+a)

- wherein

Apparent weight > Actual weight

 

 

 

for upwards w= m(g+a) = 60 (10+2)

                     w= 60X12 = 720 w

for downwards w= m(g-a) = 60 (10-2)

                     w= 60X8 = 480 w


Option 1)

720 N and 480 N

correct option

Option 2)

480 N and 720 N

Incorrect option

Option 3)

600 N and 600 N

Incorrect option

Option 4)

None of these

Incorrect option

Posted by

divya.saini

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