Answer:
d
Step-by-step explanation:
The total distance covered is 6 m
<u>Step-by-step explanation:</u>
Let the total distance be '2d'
Total time = 1.25hrs
Downhill speed = 6 mphr
Uphill speed = 4 mphr
(d/6) +(d/4) = 1.25
(2d + 3d) /12 = 1.25
5d/12 = 1.25
d = 3m
So, 2d = 6 m
The total distance covered is 6 m
Answer:
8
Step-by-step explanation:
trust me
Answer:
It takes 3 seconds over the interval [0,3]
Step-by-step explanation:
To find when the roller coaster reaches the ground, find when d=0.
![0=144-16t^2](https://tex.z-dn.net/?f=0%3D144-16t%5E2)
To solve divide each term by 16 and factor:
![\frac{0}{16}=\frac{144}{16} -\frac{-16t^2}{16} \\0= 9 - t^2\\0=(3-t)(3+t)](https://tex.z-dn.net/?f=%5Cfrac%7B0%7D%7B16%7D%3D%5Cfrac%7B144%7D%7B16%7D%20-%5Cfrac%7B-16t%5E2%7D%7B16%7D%20%20%5C%5C0%3D%209%20-%20t%5E2%5C%5C0%3D%283-t%29%283%2Bt%29)
Solve for t by setting each factor to 0.
t-3=0 so t=3
t+3=0 so t=-3
This means the car is in the air from 0 to 3 second.