Question

Superman strikes a golf ball on the ground at a 38 degree angle above the horizontal at 147 m/s. What is the maximum height the golf ball reaches?

255 m


418 m


687 m


1103 m

Answer 1

The ball is hit with an initial vertical velocity of

(147 m/s) sin(38º) ≈ 90.5 m/s

Recall that

v ² - u ² = 2 a ∆y

where u and v are initial and final velocities, respectively; a is acceleration; and ∆y is displacement.

Vertically, the ball is in freefall, so it is only subject to acceleration due to gravity, with magnitude g = 9.80 m/s² in the downward direction. At its maximum height, the ball has zero vertical velocity (v = 0) and the displacement is equal to the maximum height, so

0² - (90.5 m/s)² = 2 (-g) ∆y

∆y = (90.5 m/s)² / (2g)

∆y ≈ 418 m