Question

What must be the nozzle velocity of the water from a fire hose if it is to reach a point 30m directly above the nozzle?

Answer 1

use one of the equations of motion for constant accelaeration

in this case this is acceleration due to gravity 9.81 m s^-2


v^2 = u^2 + 2as

u = initial velocity =?
final velocity v = 0
acceleration = -9.81
distance s = 30

plug these values into above equation and solve for u

Answer 2

so you have
0 = u^2 - 2*9.81*30

Answer 3

so u^2 = 588.6

take the square root and you have it

Answer 4

Thank you, makes sense