calculate the range of the projectile using the initial speed and angle. use 9.8m/s. Initial speed 18m/s and the is 75 degrees. I came up with 8.29 is that right

At the max. height, Vf = o.

Vf^2 = Vi^2 + 2gah = o,
(18)^2 + 2*(-9.8)h = 0,
324 - 19.6h = 0,
-19.6h = -324,
h = -324 / -19.6 = 16.5m = Range.

Your ans. is twice mine; check your math for error.

To calculate the range of a projectile, you can use the following formula:

Range = (initial speed^2 * sin(2*angle))/gravity

Given the information you provided:
Initial speed (u) = 18 m/s
Angle (θ) = 75 degrees
Gravity (g) = 9.8 m/s^2 (as given)

First, we need to convert the angle from degrees to radians, since the trigonometric functions in most programming languages use radians.

Angle (in radians) = θ * (π/180)

So in this case:
Angle (in radians) = 75 * (π/180) ≈ 1.3089 radians

Now we can substitute the values into the formula:

Range = (18^2 * sin(2 * 1.3089))/9.8

Calculating further:
Range = (324 * sin(2.6178))/9.8
Range = (324 * 0.9093)/9.8
Range ≈ 29.9918 meters

Therefore, the range of the projectile, rounded to two decimal places, is approximately 29.99 meters.

It seems you made an error in your calculation. The correct answer is approximately 29.99 meters, not 8.29.