Motion in Two or Three Dimension : Projectile motion

1. The problem statement, all variables and given/known data



A projectile is launched at a 60° angle above the horizontal on level ground. The change in its velocity between launch and just before landing is found to be Δv^→ = v^→_landing _ v^→_launch = -20 y^{^} m/s .

What is the initial velocity of the Projectile ?

What is its final velocity just before landing ?

2. Relevant equations



Δv^→ = v^→_landing _ v^→_launch = -20 y^{^}

m/s .

3.The attempt at a solution

I considered :

V_ox + V_fx = 0 and V_oy + V_fy = -20

knowing that V²_fy - V²_oy= -2g (Y_f-Y_o) But I couldn't go further

1. The problem statement, all variables and given/known data







2. Relevant equations







3. The attempt at a solution