A projectile is fired with an initial velocity of 30 m/s at 60 degrees to the horizontal. At the projectile's highest point what is its velocity and acceleration?

Does the distance travelled by an oscillating mass between times t=0 and t2 equal the displacement of the particle over the same time period if t2> t/2? hint: consider a sine wave starting at t1=0, then consider a closing wave starting at t1=0, for your explanation.