Projectile Motion: Minimum Velocity for Overcoming an Obstacle

[Jerry Smith]

Homework Statement

A projectile needs to be launched over a fence of width d, and height y. Find the minimum velocity needed.

Homework Equations

Projectile Motion etc..

The Attempt at a Solution

[/B]
x(t) = v_0xt
y(t) = -½gt²+v_oyt

Setting:

x(T) = L
y(T) = h

 

[paisiello2]

Maybe provide a diagram and define what T, L, and h are.

 

[haruspex]

As paisiello2 says, think about how the trajectory will relate to the fence. Draw yourself a diagram, even if you don't post it.
You need to create a collection of variables to represent all the unknown launch parameters. What are they?
You will also need variables for any unknowns that help you connect the horizontal constraints with the vertical ones (like, time to reach a certain point).
Then you can write some equations using the variables you created and expressing the trajectory constraints.