Question

The gravitational force exerted on a baseball is 2.24 N down. A pitcher throws the ball horizontally with velocity 17.0 m/s by uniformly accelerating it along a straight horizontal line for a time interval of 183 ms. The ball starts from rest.

(a) Through what distance does it move before its release?
__________m
(b) What are the magnitude and direction of the force the pitcher exerts on the ball?
magnitude______N
direction_______° above the horizontal

Answer 1

Vertical force = weight of the ball
F = ma
2.24 = m x 9.81
mass of ball = 0.23 Kg
(a) Acceleration of ball:
(v - u)/t
= (17 - 0)/0.183
= 92.9 m/s²
Using equation of motion:
2as = v² - u², where u is 0 because initially at rest.
s = 17²/(2 x 92.9)
s = 1.56 m

(b) F = ma
= 0.23 x 92.9
= 21.4 N in the direction of motion of the ball
tan(∅) = y-component/x-component
∅ = tan⁻¹ (-2.24/21.4)
= -5.98° from the horizontal