Answer to Question #135414 in Mechanics | Relativity for Dominik

Question

A baseball is hit so that it travels straight upward after being struck by the bat. A fan observes that it takes 3.00 s for the ball to reach its maximum height. Find (a) the ball’s initial velocity and (b) the height it reaches.

Answer 1

a) The speed with an equally accelerated movement and the presence of an initial speed is determined by the formula: $V_1=V_0-g\times t$ , since the speed at the maximum height is zero, that is, $V_1=0$ , then

$0=V_0-g\times t$ ;

$V_0=g\times t=10\times 3=30$ m/s.

b) Since the distance travelled by the body with equal motion is determined by the formula $S = V _ 0\times t-\frac {g\times t ^ 2} {2}$ , the maximum height will be reached at the upper point, therefore

$h=30\times 3-\frac{10\times 3^2}{2}=45$ m.