Question

A light shines from the top of a pole 30 ft high. A ball is dropped from the same height from a point 20 ft away from the light. How fast is the shadow of the ball moving along the ground one half sec​ later? (Assume the ball falls a distance s equals 16 t squared in t​ sec.)

Answer 1

Answer: if this makes sense  dx/dt = -1500 ft/sec

Explanation: The shadow is moving at a speed 1500 ft/sec towards  

the point immediately below the ball. The high speed is to be expected  

since initially the shadow is at infinity and has to move to the end  

point in 1.76 seconds.