Posted by Franklin on .
1. A certain projectile is launched with an initial speed v0. At its highest point its speed is v0/6. What was the launch angle?
2. The "hang time" of a punt is measured to be 3.50 s. If the ball was kicked at an angle of 61.0° above the horizontal and was caught at the same level from which it was kicked, what was its initial speed? (Neglect air resistance.)

physics 
Elena,
1.The speed at the highest point is equal to v(x) since v(y) = 0 =>
v(x)=v₀/6.
v₀(x) =v(x) =v₀•cosα= v₀/6.
cosα=1/6=0.167,
α =arccos0.167=80.41°.
2.
t= 2vₒ•sinα/g
vₒ=g•t/2•sinα=9.8•3.5/2•sin61°=19.6 m/s