149k views
3 votes
A car traveling at 12 m/s accelerates uniformly until it reaches 19 m/s. The car travels a distance of 48 m while accelerating. How long did the car accelerate for?

A) 3 seconds
B) 4 seconds
C) 5 seconds
D) 6 seconds

User Mubo
by
7.8k points

1 Answer

3 votes

Final answer:

The car accelerated for approximately 3.098 seconds.

Step-by-step explanation:

In this problem, we have a car that starts at an initial velocity of 12 m/s and accelerates uniformly until it reaches a final velocity of 19 m/s. The car travels a distance of 48 m while accelerating. We can use the equation:

vf = vi + at

where vf is the final velocity, vi is the initial velocity, a is the acceleration, and t is the time.

Plugging in the given values, we have:

19 m/s = 12 m/s + a * t

Subtracting 12 m/s from both sides, we get:

7 m/s = a * t

Dividing both sides by a, we get:

t = 7 m/s / a

Since the car travels a distance of 48 m while accelerating, we can use the equation:

vf^2 = vi^2 + 2a * d

where d is the distance.

Plugging in the given values, we have:

19^2 = 12^2 + 2a * 48

Simplifying, we get:

361 = 144 + 96a

Subtracting 144 from both sides, we get:

217 = 96a

Dividing both sides by 96, we get:

a = 217 / 96

Now we can substitute the value of a into the first equation to find the time:

t = 7 m/s / (217 / 96)

Simplifying, we get:

t = 7 * 96 / 217

Calculating, we find that t ≈ 3.098 seconds.

User Dave McLure
by
7.7k points