Question

The resistance created by waves on a 120-m-long ship is tested in a channel using a model that is 4 m long Y Part A If the ship travels at 70 km/h. what should be the speed of the model?

Answer 1

Answer:

$V_m = 12.78 km/hr$

Explanation:

given,

length of the ship = 120 m

length of model of the ship = 4 m

Speed at which the ship travels = 70 km/h

speed of model = ?

by using froude's law

  $F_r = \dfrac{V}{\sqrt{L g}}$

for dynamic similarities

  $(\dfrac{V}{\sqrt{L g}})_P = (\dfrac{V}{\sqrt{L g}})_{model}$

  $(\dfrac{V_p}{\sqrt{L_p}}) = (\dfrac{V_m}{\sqrt{L_m}})$

  $(\dfrac{70}{\sqrt{120}}) = (\dfrac{V_m}{\sqrt{4}})$

          $V_m = 12.78 km/hr$

hence, the velocity of model will be 12.78 km/h