trig: 60 mph car on curve w/ 528-ft radius: dist. in 9 sec

[duckers321]

A car rounds a curve of radius 528 ft at the rate of 60 mi/h. Through how many radians does the car turn in 9 seconds?

 

[skeeter]

first, you'll have to find out how far the car travels in 9 sec ... you'll have to convert 60 mph into ft/sec.

then use the arc length formula ...

\(\displaystyle s=r\theta\)

s = arc length
r = radius
\(\displaystyle \theta = \, angle \, in \, radians\)

 

[duckers321]

okay...i got 88 ft/sec. but how does that help me find the angle in radians?

 

[stapel]

okay...i got 88 ft/sec. but how does that help me find the angle in radians?

Try using the information you've been given:

You have a rate of speed, which tells you how many feet are covered in one second, and you are given a number of seconds. Use this to find the distance.

You have a distance covered on a circle with a given radius -- in other words, you have an arc length -- and you are given a formula relating arc length (computed), radius (given), and subtended angle (which you need to find). Use this to find the number of radians.

If you get stuck, please reply showing your steps, reasoning, and how far you have gotten. Thank you!

Eliz.