6. A baseball is thrown from the outfield toward the catcher. When the ball reaches itshighest point, which statement is true? (a) Its velocity and its acceleration are both nonzero. (b) Its velocity is zero, but its acceleration is nonzero. (c) The vertical component of the velocity is zero. (d) The horizontal component of the velocity is zero.

Horizontal and vertical motions of a projectile are independent of each other. What is meant by this?

Problem In a relief operation mission involving a helicopter h distance above the ground traveling with a horizontal velocity vx. What should be the expression for the horizontal distance dy at which you release the relief package so that it will arrive to the survivors at the right place? (Neglect the effect of air resistance) Solution To determine this, we must first derive the time it takes for the relief package to reach the survivors. We use this equation -h = Vịnitial-yt + (1/2)ay If we just drop the package from the helicopter, the equation above becomes + (1/2)ay Substituting ay = -g then simplifying results to t = sqrt( which is the time it takes for the object to reach the ground. Since the package will just travel at a constant velocity in the x-axis, thus dx = Vxt Substituting the time taken by the package to reach to ground results to: dx = ( )( sqrt ( )) which is the expression for the horizontal distance at which you should drop the package.

A movie stunt driver on a motorcycle can fly over a wide ditch with certain angle and initial speed. However, if he speeds horizontally, will he crosses this ditch? Consider his motion as projectile, and the two sides of ditch have equal altitude. Yes, he will if his initial velocity is big enough No, theoretically he will never cross this ditch It depends on the weather condition It depends on how powerful of his motorcycle Is it 1,2,3, or 4