Calculating Height h from a Projectile Launched at A

[Alexanddros81]

Homework Statement

A projectile launched at A with an initial velocity of 24 m/s at the angle θ=60deg, impacts the vertical wall at B. Neglecting air resistance, calculate the height h

Homework Equations

The Attempt at a Solution

Here is my solution

As you can see to find height h I assumed that $v_y=0$ in the second of Eqs. (f) and solved for time.
Is this correct or should I have solved first equation of (g) to find time and then solve for y?

 

[haruspex]

I assumed that $v_y=0$

Then don't. There is no basis for such an assumption.
Yes, find t first.

 

[kuruman]

Look at your equations labeled (e). The first equation can be used to find an expression for t in terms of x and θ. Substitute that in the second equation and you will have y as a function of x and θ. Substitute the given numbers for x and θ to find h.

 

[Alexanddros81]

Can you check this?

 

[cnh1995]

View attachment 208695

Can you check this?

It's correct.