[Solved] Conflicting cosine answers (yes, it's homework)

[CPA]

My daughter is working vector homework for physics. Her problem states:

A truck travels beneath an airplane that is
moving 160 km/h at an angle of 45◦ to the
ground.
How fast must the truck travel to stay be-
neath the airplane?
Answer in units of km/h.

So, we know that the formula for Vx (truck speed) is Vx = Vcos°, such that Vx = 160cos(45).

Now, when we enter this in a Ti-83 calculator we get 84.1 km/h, and when we put this in a search bar, we get the same result (google search bar has built in math answer response now). However, when we hit enter on the yahoo search bar the search result page comes up with a calculator and the answer 113.1 km/h. The 113.1 is the right answer.



We entered this formula the same way in the calculator and the search bar. Why is it that only the yahoo search result page gives us the correct answer?

EDIT: Nevermind. My daughter had the Ti set to Radian instead of Degree. sigh....

 

[Imp]

My calculator says Cos(45) is 0.707.

Edit: I typed "160cos(45)" into google... Google defaults to radians for some reason.

https://en.wikipedia.org/wiki/Radian

Check and keep track of your units, makes conversions easier. Six years of engineering...

 

[CPA]

My calculator says Cos(45) is 0.707.

you forgot the 160 in front of cos.

 

[highland145]

Thanks, CPA....I'm re-learning geometry 37 years later. Physics is going to give me incontinence.

Why can't my kid just knee cap people?