First we need to find the speed of the dolphin sound wave in the water. We can use the following relationship between frequency and wavelength of a wave:
where
v is the wave speed
its wavelength
f its frequency
Using
and
, we get
We know that the dolphin sound wave takes t=0.42 s to travel to the tuna and back to the dolphin. If we call L the distance between the tuna and the dolphin, the sound wave covers a distance of S=2 L in a time t=0.42 s, so we can write the basic relationship between space, time and velocity for a uniform motion as:
and since we know both v and t, we can find the distance L between the dolphin and the tuna:
Answer:
The work required to stretch a spring 12 ft beyond its natural length is 432 ft-lb
Explanation:
The work to stretch a spring is calculated using the formula:
Equation (1)
W = work in ft-lb
k = spring constant in lb/ft
x = spring deformation in ft
we clear k from the equation (1)
Equation (2)
We replace x = 2ft, W = 12 ft-lb in the equation (2)
Calculation of work required to stretch spring 12 ft
We replace k = 6 lb/ft and x = 12ft in the equation (1)
I believe it is surface waves because it happens at the surface of the water.