Question

A firework is launched at the rate of 10 feet per second from a point on the ground 50 feet from an observer. To 2 decimal places in radians per second, find the rate of change of the angle of elevation when the firework is 40 feet above the ground. Type your answer in the space below. If your answer is a number less than 1, place a leading "0" before the decimal point (ex: 0.35).

Answer 1

at height h,

tanθ = h/50

sec^2θ dθ/dt = 1/50

so, plug in your numbers and evaluate dθ/dt