Calculus Related Rates - How Fast is the Angle of Elevation Changing

This video shows how to solve a related rate problem. How fast is the angle of elevation increasing.

[dolphinpinkse]

Thank you so much. This helped me a lot!!

[jeffzyzzos]

For everyone who is confused about the units used. Radian is the SI unit for theta. You’re gonna have to memorise it to use for units of rates of angles. The question uses seconds as a measurement. Therefore, the measurement of dθ/dt will be rad/s.

[johnnolen]

I think I would have used the identity sec^2θ = 1 + tan^2θ. Then 1 + tan^2θ = 1 + (h/200)^2. It follows that 34/25·dθ/dt = 4/200. Therefore dθ/dt = (25/34)(4/200) = 1/68 rad/second. ◼

[pagapulaanrohans.]

Is radians per second the "default" unit when knowing the rate of change in an angle measure? What if the initial given uses km/min, should I convert it to that? and how do u do it o.o

[hoantran]

Could you explain for me why the unit is radian/ second? Why is radian in there?

[ahmadkhaled]

Why at the first line we did bot replace h with its value 120