A skateboard halfpipe is being designed for a competition. The halfpipe will be in the shape of a parabola and will be positioned above the ground such that its focus is 20 ft above the ground. Using the ground as the x-axis, where should the base of the halfpipe be positioned? Which equation best describes the equation of the halfpipe?

Option A , (0, 20); y equals one over eighty times x squared plus 20

Step-by-step explanation:

The equation of parabola is given by  

(X-h)^2 = 4p(Y-k)^2

In this case h = 0  

So we get  

Y = X^2/4P +k

Focus point is (h, p+k) , p+k = 40  

Hence h, k = (0,20)

P = 40-k = 20

Equation Y = X^2/80 +20  

Hence, option A is correct

38.6°

step-by-step explanation:

resultant is 10 pound

smaller force = 8 pound

angle formed = tan⁻¹(

                        =tan⁻¹(

                          =tan⁻¹(0.8)

                        =38.6°