assuming 50% efficiency, 150 kcals of chemical energy would result in __________ of kinetic energy.\na. 50…
assuming 50% efficiency, 150 kcals of chemical energy would result in __________ of kinetic energy.\na. 50 kcals\nb. 75 kcals\nc. 100 kcals\nd. 150 kcals\nplease select the best answer from the choices provided.
Answer
Explanation:
Step1: Recall efficiency formula
Efficiency = $\frac{\text{useful output energy}}{\text{input energy}}\times100%$. We want to find the useful output (kinetic energy), and we know efficiency = 50% or 0.5, and input energy = 150 kcals.
Step2: Rearrange formula to solve for output
Let kinetic energy be $E_{k}$. From Efficiency = $\frac{E_{k}}{\text{input energy}}\times100%$, we can rewrite it as $E_{k}=\text{efficiency}\times\text{input energy}$. Substitute efficiency = 0.5 and input energy = 150 kcals. So $E_{k}=0.5\times150$ kcals.
Step3: Calculate kinetic energy
$E_{k}=75$ kcals.
Answer:
B. 75 kcals