We can eliminate choice C because our parabola is not upside down. The way I determined which one it was was by picking a point on the graph and testing the x value of the point in the equation. If the y value on the graph was the same as the y value on my calculator, then I chose the right one. Let me give you an example of what doesn't work first. Let's pick (3, 2) from the graph. Let's test that point in choice D. Filling in x = 3, y should = 2 if that's the right equation.
![\frac{1}{2}(3^2)-3+2= \frac{7}{2}](https://tex.z-dn.net/?f=%20%5Cfrac%7B1%7D%7B2%7D%283%5E2%29-3%2B2%3D%20%5Cfrac%7B7%7D%7B2%7D%20%20)
. Our y coordinate is not 7/2, it's 2. Let's try A:
![\frac{1}{3}(3^2)-3-2=-2](https://tex.z-dn.net/?f=%20%5Cfrac%7B1%7D%7B3%7D%283%5E2%29-3-2%3D-2%20)
. Again, our y value is 2, not -2. Let's try B:
![\frac{1}{3}(3^2)-3+2=2](https://tex.z-dn.net/?f=%20%5Cfrac%7B1%7D%7B3%7D%283%5E2%29-3%2B2%3D2%20)
. See how that works? Your choice is B.
As the comments state, the velocity is the derivative of the position.
Therefore, the velocity as function of time is:
ds / dt = 24 + 6t - 3t^2.
That is a parabola whose maximum is (1,27). With that you know that the velocity will never be either 63 m/s or 81 m/s.
Also, you know that the velocity at t = 1 s is 27 m/s.
And, you can also find that the velocity at t = 3 is 15 m/s.
I am confident on that this analysis solves your question. Else, insert a comment.
3/5 of the ride = 15 km
1/5 of the ride = 15 ÷ 3 = 5km
5/5 of the ride = 5 x 5 = 25km
Answer: the ride is 25km
D is the answer of your question
Answer:
C. 1
Step-by-step explanation:
We can see that each box in the grid is one unit.
We count one box to the right on the horizontal axis and 4 boxes down on the vertical axes to obtain the components of vector v.
See graph in attachment.
Therefore the components of vector v is
![\binom{1}{-4}](https://tex.z-dn.net/?f=%5Cbinom%7B1%7D%7B-4%7D)
.
The length of the x component is 1 unit
Hence the correct answer is C.