Question

question 7 of 10
two people playing a game of table tennis make up a closed system with 12,175 j of energy. at the beginning of the game the system has 9,875 j of me. at the end it has 8,430 j of me. how much of the total energy was transformed into thermal energy during the game?
a. 1,445 j
b. 3,745 j
c. 10,730 j
d. 2,300 j

Explanation:

Step1: Recall energy - conservation in a closed - system

In a closed system, the total initial energy equals the total final energy. The change in mechanical energy (ME) is converted into thermal energy.

Step2: Calculate the change in mechanical energy

The initial mechanical energy is $E_{i - ME}=12175\ J$ and the final mechanical energy is $E_{f - ME}=8430\ J$. The change in mechanical energy $\Delta E_{ME}=E_{i - ME}-E_{f - ME}$.
$\Delta E_{ME}=12175 - 8430$
$\Delta E_{ME}=3745\ J$

Answer:

B. 3,745 J