Question

Morning breakfast gives 5000 cal to a 60 kg person. The efficiency of person is 30%. the height upto which the person can climb up by using energy obtained from breakfast is?

Ans 10.5 m

How?

Answer 1

Here,

Energy of the man, E = 5000 cal = 20920 J

Mass of the man, m = 60 kg

Let the man climb to height ‘h’.

So, energy utilized by the man is = mgh

Since, the efficiency of the man is 30% and he uses all his energy, so,

mgh = (30/100)E

=> (60)(9.8)(h) = (0.3)(20920)

=> h = 10.6 m