Solution Found!
Searchlight problem—narrow beam A searchlight is 100 in
Chapter 7, Problem 42E(choose chapter or problem)
A searchlight is 100 m from the nearest point on a straight highway (see figure). As it rotates, the searchlight casts a horizontal beam that intersects the highway in a point. If the light revolves at a rate of \(\pi / 6\) rad/s, find the rate at which the beam sweeps along the highway as a function of \(\theta\). For what value of \(\theta\) is this rate minimized?
Questions & Answers
QUESTION:
A searchlight is 100 m from the nearest point on a straight highway (see figure). As it rotates, the searchlight casts a horizontal beam that intersects the highway in a point. If the light revolves at a rate of \(\pi / 6\) rad/s, find the rate at which the beam sweeps along the highway as a function of \(\theta\). For what value of \(\theta\) is this rate minimized?
ANSWER:
Solution 42E Step 1: Given data S is the searchlight,P is the person and triangle QPS is the right angled triangle The searchlight rotates when the person is 100 meters from the searchlight Angular velocity of the searchlight, dt = 6ad/sec