Question

The great, gray-green, greasy Zambezi River flows over Victoria Falls in south central Africa. The falls are approximately 107 m high. If the river is flowing horizontally at 3.70 m/s just before going over the falls, what is the speed of the water when it hits the bottom? Assume the water is in free fall as it drops.

HW 4.4 Problem Solving 4.84 7 of 7 Constants PartA The great, gray green, greasy Zambezi River flows over Victoria Falls in south central Africa. The falls are approximately 107 nm high If the river is flowing horizontally at 3.70 m/s just before going over the falls, what is the speed of the water when it hits the bottom? Assume the water is in free fall as it drops. m/s Submit < Return to Assignment Provide Feedback

Answer 1

Let us consider the downward direction as positive.

Gravitational acceleration = g = 9.81 m/s²

Initial velocity of the water = V₁ = 3.7 m/s

The river is flowing horizontally.

Initial horizontal velocity of the water = V_1x = 3.7 m/s

Initial vertical velocity of the water = V_1y = 0 m/s

Height of the falls = H = 107 m

Time taken by the water to hit the bottom = T

H = V_1yT + gT²/2

107 = (0)T + (9.81)T²/2

T = 4.67 sec

Velocity of the water when it hits the bottom = V₂

Horizontal velocity of the water when it hits the bottom = V_2x

There is no force acting on the water in the horizontal direction therefore the horizontal velocity is constant.

V_2x = V_1x = 3.7 m/s

Vertical velocity of the water when it hits the bottom = V_2y

V_2y = V_1y + gT

V_2y = 0 + (9.81)(4.67)

V_2y = 45.813 m/s

$V_{2} = \sqrt{(V_{2x})^{2} &plus; (V_{2y})^{2}}$

$V_{2} = \sqrt{(3.7)^{2} &plus; (45.813)^{2}}$

V₂ = 45.96 m/s

A) Speed of the water when it hits the bottom = 45.96 m/s

Answer 2

yes this is the answer, yes.