Explanation:
the other 40% is used to power the 60% making it only capable of 60% efficiency
Answer:

Explanation:
Given:
- mass of car,

- distance of skidding after the application of brakes,

- coefficient of kinetic friction,

<u>So, the energy dissipated during the skidding of car:</u>
<em>Frictional force:</em>

where N = normal reaction by ground on the car


<em>Now from the work-energy equivalence:</em>


is the dissipated energy.
A) Agreed.
<span>b) Value agreed but units should be W (watts). </span>
<span>c) Here's one method... </span>
<span>15 miles = 24140 m </span>
<span>1 gallon of gasoline contains 1.4×10⁸ J. </span>
<span>So moving a distance of 24140m requires gasoline containing 1.4×10⁸ J </span>
<span>Therefore moving a distance of 1m requires gasoline containing 1.4×10⁸/24140 = 5800 J </span>
<span>Overcoming rolling resitance for 1m requires (useful) work = force x distance = 1000x1 = 1000J </span>
<span>So 5800J (in the gasoline) provides 1000J (overcoming rolling resistance) of useful work for each metre moved. </span>
<span>Efficiency = useful work/total energy supplied </span>
<span>= 1000/5800 </span>
<span>= 0.17 (=17%) </span>
Bruh ima be honest with you idek