Question

a) Is your mass times the gravitational acceleration of the Earth greater than, less than, or equal to the normal force exerted on you by the chair you are sitting on? Explain.

b) A classmate of yours asks you why we have ignored this acceleration for the whole first term of physics. “Is everything we’ve learned a lie?” they ask. Assuage their fears by calculating the percent- age difference between the normal force from the chair and your weight.

Answer 1

a) on you when sitting on the chair is given by Forces acting FN mg 'Fg-mg The mass times the gravitational acceleration is given by, mg Thus, mass times the gravitational acceleration of the Earth is equal to the normal force exerted on you by the chair you When the person is sitting the chair exerts the normal force which balances this force. Thus, it is absolutely equal the person's weight sitting the chair, his weight are on. acts in the downward direction, and on to (b) The difference between the normal force from the chair and weight is given by Fx-W =mg-mg =0 Thus, in percentage x100 = 0% 100 So, it shows that weight is equal to the normal force