Question

assuming 50% efficiency, 150 kcals of chemical energy would result in ______ of kinetic energy. a. 50 kcals b. 75 kcals c. 100 kcals d. 150 kcals please select the best answer from the choices provided.

Explanation:

Step1: Recall efficiency formula

Efficiency = $\frac{\text{useful output energy}}{\text{input energy}}\times100\%$. We know efficiency = 50% or 0.5, and input energy (chemical energy) = 150 kcals. Let the kinetic energy (useful output energy) be $E$.

Step2: Rearrange formula to solve for $E$

From efficiency formula $0.5=\frac{E}{150}$, then $E = 0.5\times150$.

Step3: Calculate $E$

$E=75$ kcals.

Answer:

B. 75 kcals