Question

A typical candy bar contains 300 Calories (300kcal). If this energy could be used with 100% efficiency in doing work against gravity on a 1500kg automobile, how high could it be lifted?

Answer 1

The car can be lifted to a height of 85.4 m

Explanation:

We start by converting the energy of the candy bar from kcal to Joules.

Knowing that:

1 kcal = 4184 J

The energy of the candy bar is

$E=300 kcal \cdot 4184=1.26\cdot 10^6 J$

The work done when lifting the car is equal to the gain in gravitational potential energy of the car, therefore:

$W=mg\Delta h$

where

m = 1500 kg is the mass of the car

$g=9.8 m/s^2$ is the acceleration of gravity

$\Delta h$ is the change in height of the car

The energy of the candy bar here is entirely use to lift the car, since the efficiency is 100%, so we can find the change in height of the car:

$\Delta h = \frac{W}{mg}=\frac{1.26\cdot 10^6}{(1500)(9.8)}=85.4 m$

Learn more about gravitational potential energy:

brainly.com/question/1198647

brainly.com/question/10770261

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