Question

Calculate the force at sea level that a boy of mass 50 kg exerts on a chair in which he is sitting.

Answer 1

490 N down. i just answered it well taking the quiz.

Answer 2

As per the question the mass of the boy is 50 kg.

The boy sits on a chair.

We are asked to calculate the force exerted by the boy on the chair at sea level.

The force exerted by boy on the chair while sitting on it is nothing else except the force of gravity of earth i.e the weight of the body .The direction of that force is vertically downward.

At sea level the acceleration due to gravity g = 9.8 m/s^2

Hence the weight of the boy $w = mg$  [m is the mass of the body]

we have m = 50 kg.

                             Hence w = 50 kg ×9.8 m/s^2

                                             =490 N kg m/s^2

                                              = 490 N

Here newton [N] is the unit of force.