Question

A battery weighing 0.525 lb can store 30.8 kcal of electrical energy. What is the energy density of the battery in Wh per kg? Give your answer to an accuracy of 3 significant figures.

Answer 1

Answer:

Energy Density: 129.412 $\frac{Wh}{kg}$

Explanation:

First of all, let's convert the battery weighing from pounds to kilograms:

0.525 lb x $(\frac{0.454 kg}{1 lb})$ = 0.238 kg

Now let's convert the electrical energy from kcal to Wh:

30.8 kcal x $(\frac{1 Wh}{1 kcal})$ = 30.8 Wh

Now we can calculate energy density as follows:

Energy Density = $\frac{30.8}{0.238}$

Energy Density = 129.412 $\frac{Wh}{kg}$