According to the label on a soft drink, one serving provides 145 kcal. If all of this energy is used to lift 1.0 kg blocks, how many blocks can be lifted 5.0 meters?

1 Answer
Feb 27, 2017

You could lift 12 369 one-kilogram blocks to a height of 5.0 m

Explanation:

This is most easily done by converting 145 kcal into joules.

#145 kcal xx 4.18 kJ/(kcal) xx 1000 J/(kJ) = 606 100 J#

To determine the energy each 1.0 kg block requires to lift it 5.0 m:

#W=mgh=(1.0 kg)(9.8 N/(kg))(5.0 m) = 49 Nm (or 49 J)#

So, with #606000 J# we could lift

#606000 J-:49 J/(block) = 12 369 " blocks"# (give or take a few)