# Could you please check my answers and units.Also, help me with 3 and 4, I don't quite understand them. Thanxs!

1. An automobile starts from rest and accelerates at 3m/s2 for 4 seconds. How fast is it going after acceleration?

-I got 12 m/s

3. At time = 0 an automobile already traveling at 30 km/hr. accelerates at 3m/s2 for 2 seconds. During these two seconds, how far does it go?

-I got 12 m/s

4. An automobile is traveling at 30 km/hr. It accelerates at 3 m/s2 until it has covered 100 meters.. What is its new velocity?

- 6030 (not sure about units)

## 3. No. distane= vi*t + 1/2 a t^2

I will be happy to critique your work. Be certain to change km/hr to m/s

4. No. vf= sqrt (vi^2 + 2*a*d)

be certain vi is in m/s units.

** I will be happy to critique your work or thinking**

## 1. To find the final velocity of an object after acceleration, you can use the formula:

Final velocity = Initial velocity + (acceleration × time)

In this case, the initial velocity is 0 m/s (since the automobile starts from rest), the acceleration is 3 m/s^2, and the time is 4 seconds.

Plugging in these values into the formula:

Final velocity = 0 + (3 × 4) = 12 m/s

So, your answer of 12 m/s is correct.

3. In this question, the automobile is already traveling at 30 km/hr (or 8.33 m/s), and then it accelerates at 3 m/s^2 for 2 seconds. To find the distance traveled during this time, you can use the formula:

Distance = Initial velocity × time + (0.5 × acceleration × time^2)

In this case, the initial velocity is 8.33 m/s, the time is 2 seconds, and the acceleration is 3 m/s^2.

Plugging in these values into the formula:

Distance = (8.33 × 2) + (0.5 × 3 × 2^2) = 36.66 meters

So, the automobile travels a distance of 36.66 meters during these two seconds.

4. In this question, the automobile is traveling at 30 km/hr (or 8.33 m/s), and it accelerates at 3 m/s^2 until it has covered 100 meters. You need to find the new velocity after covering this distance.

To find the final velocity, you can use the formula:

Final velocity^2 = Initial velocity^2 + 2 × acceleration × distance

In this case, the initial velocity is 8.33 m/s, the distance is 100 meters, and the acceleration is 3 m/s^2.

Plugging in these values into the formula:

Final velocity^2 = 8.33^2 + (2 × 3 × 100) = 69.69 + 600 = 669.69

Taking the square root of both sides to get the final velocity:

Final velocity = sqrt(669.69) ≈ 25.88 m/s

So, the new velocity of the automobile after covering 100 meters is approximately 25.88 m/s.