Question

A man of $60kg$ gains $1000$cal of energy by eating $5$ mangoes . His efficiency is $56\%$ . to what height he can jump by using this energy?

• A. $4m$
• B. $20m$
• C. $28m$
• D. $0.4m$

Answer 1

The correct option is A $4m$

Total energy of man $=1000Cal$

$=4184J$

$\because 1KCal=4184J$

Energy used by man in jumping

$=\frac{56}{100}\times 4184$

Now,

When the man jumps, his energy will get converted into potential energy

So,

if he jumps upto height 'h' then

$60\times 9.8\times h=\frac{56\times 4184}{100}$

$\Rightarrow h=\frac{56\times 4184}{100\times 60\times 9.8}$

$h=3.98m$

$\simeq 4m$