A racevar accelerates from rest to a final speed of 250km/h. What is the average acceleration of the car?
and
John beings to walk faster and accelerates at a rate of 5km/h^2. How long did it take him to reach a top speed of 12 km/h?
I didn't know how to use the formula because I didn't know where to get some of the information from because looking at it I can't really see the V1 or V2..
To find the average acceleration of the car in the first question, we need to know the initial speed (V1) and the final speed (V2). However, the question only provides us with the final speed of 250 km/h and does not specify the initial speed. Without knowing the initial speed, we cannot calculate the average acceleration.
In the second question, we know the initial speed (V1) is 0 km/h, the acceleration (a) is 5 km/h^2, and the final speed (V2) is 12 km/h. We can use the equation:
V2 = V1 + a * t
Since V1 is 0, the equation simplifies to:
V2 = a * t
Plugging in the values, we have:
12 km/h = 5 km/h^2 * t
To isolate t, we can divide both sides of the equation by 5 km/h^2:
12 km/h / 5 km/h^2 = t
The units of km/h divide out, leaving us with:
(12 / 5) h = t
Therefore, it took John (12 / 5) hours to reach a top speed of 12 km/h.
It's important to note that when solving physics problems, having all the necessary information is crucial. Sometimes, a question may not provide all the required details, making it impossible to solve the problem accurately.