Question

The approximate height, h, in meters, traveled by golf balls hit with two different clubs over a horizontal distance of d meters is given by the following functions:

seven-iron: h=-0.002d^2 + 0.3d
nine-iron: h= -0.004d^2 + 0.5d

a) at what distances is the ball at the same height when either of the clubs used?
b) what is this height?

Answer 1

a) 100 metres

b) 10 metres

Explanation:

Given: the approximate height, h, in meters, travelled by golf balls hit with two different clubs over a horizontal distance of d meters is given by the functions:
`h=-0.002d^2+0.3d\,,\,h=-0.004d^2+0.5d`

To find: distances when the ball is at the same height when either of the clubs are used. Also, to find this height

Solution:

(a)

`-0.002d^2+0.3d=-0.004d^2+0.5d\\d(-0.002d+0.3)=d(-0.004d+0.5)\\-0.002d+0.004d=0.5-0.3\\0.002d=0.2\\d=(0.2)/(0.002)=100\,\,metres`

(b)

Put d = 100 in
`h=-0.002d^2+0.3d`

`h=-0.002(100)^2+0.3(100)\\=-20+30\\=10\,\,metres`