Q18 of 27 Page 87

A person of mass 60 kg wants to lose 5kg by going up and down a 10m high stairs. Assume he burns twice as much fat while going up than coming down. If 1 kg of fat is burnt on expending 7000 kilo calories, how many times must he go up and down to reduce his weight by 5 kg?

The calories he has to burn to lose 5 kg mass



Now, as we know 1 cal = 4.2 J




Work done=


Let, while going up work done = mgh


Therefore, while coming down,


According to the question, work done


Total work done


Given,


Mass, m = 60kg


Height, h = 10m


let, g=10 m/s


While going up and coming down fat burnt



no. of times he has to go up and down=



He must go up and down 16334 times to reduce his weight by 5 kg.


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