Question

A 53.6 kg person will need to climb a 2.9 m stairway how many times to "work off" each excess Cal (kcal) consumed?

Answer 1

Each Cal (kcal) consumed is consumed by 2.75 trips up those stairs.

Explanation:

I will assume that the 2.9 m is the vertical height attained by going up the stairway. The work done going up the stairway is the amount of gravitational potential energy that you gain.

`GPE = m*g*h = 53.6 kg*9.8 m/s^2*2.9 m = 1523 J`

Converting to kcal

`1523 cancel(J) * ((0.2389 cancel"cal")/(1 cancel(J)))*((1 kcal)/(1000 cancel(cal))) = 0.3639 kcal`

Now, let's convert 1 kcal to trips up the stairway.

`1 cancel(kcal) *((1 "trip up the stairway")/(0.3639 cancel(kcal))) = 2.75 " trips up those stairs"`

I hope this helps,
Steve