Question
A helicopter pilot drops a package when the helicopter is 200 ft. above the ground, rising at 20 ft/sec.
How long will it take for the package to hit the ground? What is the speed of the package at impact?
I know you set s(t) equal to zero, so -16(t^2)+20t+200=0, but factoring it out I get really obscure values for t. I'm wondering if there's another way to do it.
How long will it take for the package to hit the ground? What is the speed of the package at impact?
I know you set s(t) equal to zero, so -16(t^2)+20t+200=0, but factoring it out I get really obscure values for t. I'm wondering if there's another way to do it.
Answers
Reiny
-16t^2+20t+200=0
divide by -4
4t^2 - 5t - 50 = 0
This does not factor, so use the formula
t = (5 ± √825)/8
= 4.2 or a negative
but since t > 0
t = 4.2 seconds
divide by -4
4t^2 - 5t - 50 = 0
This does not factor, so use the formula
t = (5 ± √825)/8
= 4.2 or a negative
but since t > 0
t = 4.2 seconds