Physics: A car travels 120 mi averaging a certain speed. If the car had gone 10 mph faster, the trip would have taken 1 hr less. Find the car s average speed.

I’m not exactly sure but i do know that Elastic potential energy is proportional to both the restorative force & the amount of deformation...

A car travels 120 mi averaging a certain speed. If

clairesmom

30.01.2022

The average speed of a car will be "30 mph".

Explanation:

The given values are:

Distance = 120 mi

Let the speed be "x".

As we know,

$Time = \frac{Distance}{Speed}$

$=\frac{120}{x}$

According to the question,

If the speed of a car = x + 10

then the time will be:

= $\frac{120}{x} -1$

Now,

⇒ $Speed\times Time=(x+10)(\frac{120}{x}-1)$

⇒ $120=120+\frac{1200}{x} -x-10$

On multiplying "x" both sides, we get

⇒ 120x=120x+1200-x^2-10x

⇒ x^2+10x-1200

⇒ x^2+40x-30x-1200=0

⇒ x(x+40)-30(x+40)=0

⇒ (x+40)(x-30)=0

x+40=0

x=-40

Or,

x-30=0

x=30

So that the average speed will be "30 mph".

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