Projectile motion maximum range

[Willian93]

Homework Statement

a projectile is launched from level ground at some angle to the horinzontal. Which of the following must be zero for a projectile to achieve maximum range?

vx, vy, delta dx, delta dy or a

Homework Equations

The Attempt at a Solution

i thought to achieve maximum range, the vx component has to be really large, maybe vy is zero. But the answer was delta dy, not sure how it works

 

[JaredJames]

Could you elaborate what the notation values are?

I'm familiar with the equations, but not your notation.

Jared

 

[jmb88korean]

I'm assuming that since you do not have an angle, the problem is going on the basis that as you decrease your delta y, delta x increases. Think like this. Maximum range is always at 45 degrees, however since we don't know if the projectile was launched at 45 degrees, we must simply assume that the if delta y gets lower (thus a lower angle) the range will increase.