Posted by **soffy** on Monday, June 11, 2012 at 10:00am.

A police cruiser hunting for a suspect pulls over and stops at a point 10 ft from a straight wall.

The flasher on top of the cruiser revolves at a constant rate of 75 /second, and the light beam casts a spot of light as it strikes the wall.

How fast is the spot of light moving along the wall at a point 50 ft from the point on the wall closest to the cruiser?

<---10--->

- calculus -
**Steve**, Monday, June 11, 2012 at 11:15am
If x is the distance from the closest point on the wall, then

x = 10 tanθ

dx/dt = 10 sec^2θ dθ/dt

when x=50, tanθ = 5, so secθ = √26

dx/dt = 10(26) (75)(2π) = 39000π ft/sec

## Answer This Question

## Related Questions

- math calc - A police cruiser hunting for a suspect pulls over and stops at a ...
- Physics - a speeding car is driving at 120 km/h when it passes a police cruiser ...
- calculus - A police cruiser, approaching a right –angled intersection from the ...
- Math - 1. 1. A police cruiser approaching a right-angled intersection from the ...
- Physics - A car is speeding at 33.4 m/s. A police car starts in pursuit from ...
- Physics - A police cruiser is travelling at 24 m/s and slows down at a rate of 0...
- Physics - A police cruiser is travelling at 24 m/s and slows down at a rate of 0...
- physics - A police cruiser is travelling at 24 m/s and slows down at a rate of 0...
- calculus - Two roads intersect at an angle of 48º. A car and truck collide at ...
- Calculus AB - A police car is chasing a suspect. The policemen is at point y=0.6...

More Related Questions