Draw a diagram.
Review your basic trig functions. See which ones involve the quantities you are given.
When the beam is at a distance x from the closest spot on the wall,
x/20 = tanθ
so,
dx/dt = 20 sec^2θ dθ/dt
so, find sec^2θ when x=50, and you know that dθ/dt = π/2
so, plug and chug
A police cruiser hunting for a suspect pulls over and stops at a point 20 ft from a straight wall. The flasher on top of the cruiser revolves at a constant rate of 90 deg/sec, 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?
Im having difficulties on what to do with the theta, only thing i know is it might include SOHCAHTOA, thank you if anyone can help
1 answer
1 answer