The work done by the elephant to lift one log is the force multiplied by the height at which the log has been lifted:

And so, the total work done to lift the 7 logs is 7 times the work done to lift each log:
Hey there!
Here is your answer:
<u><em>The proper answer to this question is option C "</em></u><span><u><em>0.00349".</em></u>
Reason:
</span><span><u><em>1 L = 100 cL. Or 1 cL = 0.01 L</em></u>
</span><span><u><em>34.9 cL = 34.9 / 100 L = 0.349 L</em></u>
</span><span><u><em> 1 hL = 100 L. 0.349 L = 0.349 / 100 hL = 0.00349 hL</em></u>
<em>Therefore the answer is option C!</em>
If you need anymore help feel free to ask me!
Hope this helps!
~Nonportrit</span>
We can calculate this with the law of conservation of energy. Here we have a food package with a mass m=40 kg, that is in the height h=500 m and all of it's energy is potential. When it is dropped, it's potential energy gets converted into kinetic energy. So we can say that its kinetic and potential energy are equal, because we are neglecting air resistance:
Ek=Ep, where Ek=(1/2)*m*v² and Ep=m*g*h, where m is the mass of the body, g=9.81 m/s² and h is the height of the body.
(1/2)*m*v²=m*g*h, masses cancel out and we get:
(1/2)*v²=g*h, and we multiply by 2 both sides of the equation
v²=2*g*h, and we take the square root to get v:
v=√(2*g*h)
v=99.04 m/s
So the package is moving with the speed of v= 99.04 m/s when it hits the ground.