Question

One ounce of a well-known breakfast cereal contains 103 Calories (1 food Calorie = 4186 J). If 1.6% of this energy could be converted by a weight lifter's body into work done in lifting a barbell, what is the heaviest barbell that could be lifted a distance of 1.8 m?

Answer 1

Answer:

the heaviest barbell that could be lifted  is 390.6kg

Explanation:

Hello!

To solve this question you must follow the following steps

1. Find the amount of energy that can transform the body into motion, this is achieved by multiplying the breakfast consumed by the percentage of energy conversion.

$W=(103Calories)(0.016)\frac{4186J}{1calorie} =6898.5J$

2. We use the equation that defines the work done by a body that has weight when it is lifted, this is defined by the product of mass by gravity by height.

W=mgh

where

W=work=6898.5J

m=mass

g=gravity=9.81m/s^2

h=height=1.8m

now we solve for mass, and use the values.

$m=\frac{W}{hg} =\frac{6898.5}{(1.8)(9.81)} =390.6kg$

the heaviest barbell that could be lifted  is 390.6kg