Question

Solution incoming..Need to figure out what I'm doing wrong.

Answer 1

A driver needs to drive her car across a 180m long canyon. The side of the canyon opposite his starting point is 40m lower than the side that he's starting on. His initial speed is 50 m/s. At what smallest possible angle should a ramp be built so that he makes it across the canyon.

Answer 2

So this is what I did..

Answer 3

\[V_{iy}=V_{i}Sin\theta\]
\[V_{ix}=V_{i}Cos\theta\]
\[y=-40m\]
\[x=180m\]
\[V_i=50(m/s)\]
\[\theta-?\]

Answer 4

\[y = V_{iy}t+(1/2)at^2=>-40=V_{iy}t-4.9t^2\]

Answer 5

\[V_{iy}=V_iSin\theta=50Sin\theta\]
\[-40=50(Sin\theta)t-4.9t^2\]
\[x=V_{ix}t+(1/2)at^2=V_{ix}t=>180=50(Cos\theta)t=> t=18/(5Cos\theta)\]

Answer 6

After I plug in the value of t into:
\[-40=50(Sin\theta)t-4.9t^2\]
differentiate and solve for t, i get a crazy answer. Does anyone know why?

Answer 7

@TuringTest @anemonix

Answer 8

@AccessDenied @satellite73 @amistre64

Answer 9

Gotta run to a store, will be back in about half an hour, would appreciate it if anyone could take a look at this and tell me what's wrong with my solution.

Answer 10

yay Turing's here

Answer 11

give me a minute to finish breakfast plz

Answer 12

Ok lol.. i just started eating breakfast too actually hahah

Answer 13

first thing I gonna do when my hands are more free is draw it... I always draw it

Answer 14

>.> i got 8.27 degrees actually.