question_answer

A person of mass 42 kg eats bananas of 980 cal. If this energy is used up to lift him from the ground, the height to which he can climb is ???.

Answer:

Energy\[=980\,\,cal=980\times 4.2\,\,J\] Work done \[=mgh\] \[\Rightarrow Energy=mgh\Rightarrow 980\times 4.2=42\times 9.8\times h\] \[\Rightarrow h=10\,\,m.\]