Question

Problem-3 Ariana is budgeting her energy costs. She thinks about how much energy she uses by just climbing up the stairs to the BRI 282 lab. In order to neither gain nor lose any body weight by going to the BRI 282 lab room, she needs to replace the energy she uses in climbing with food energy. Although she always otherwise ents sensibly, she decides that she will specifically replace the cost of energy to climb up to the BRI 282 lab room with the cost of chocolate. She notices that Walmart is selling Hershey bars, which supply 220Cal of energy on-average at $0.88 for each 1.5oz bar. If Ariana weighs 115lb, and the BRI 282 lab is 4.0m above the ground, how many times can Ariana climb up to the BRI 282 lab room for each $1.00 of chocolate she eats?

Answer 1

So, The total energy she needs to go to the lab = mgh

= 115 * 0.45 (kg) * 10* 4

= 2070 J.

Now, she gets 220 Calories for 0.88 $

So, for 1$ she gets (1/0.88) *220 C

= 250 Calories

= 250 *4.18 J

=1045 J.

So, number of times she can climb to the lab with energy from the 1$ bar = 2070/1045 = approximately 2 times.