Water drips from rest from a leaf that is 15 meters above the ground. Neglecting air resistance, what is the speed of each water drop when it hits the ground?
A)30 m/s
B)17 m/s
C)40 m/s
D)15 m/s
E)20 m/s

Question

Quizplus · Accepted Answer

Using the kinematic equation,
v^2 = u^2 + 2as
Here, u=0 (drop is at rest initially), a = -9.8 m/s^2 (acceleration due to gravity) and s = 15 m (height of the leaf from the ground).
Plugging in the values we get,
v^2 = 2*(-9.8)*15
v^2 = -294
v = sqrt(-294) (taking square root of both sides, as velocity cannot be negative)
v = 17.18 m/s (approx.)
Therefore, the speed of water drops when they hit the ground is approximately 17 m/s. Hence, option B is the correct choice.

Water Drips from Rest from a Leaf That Is 15