The answer is c. it requires no works
Answer:
Check the explanation
Explanation:
This is the step by step explanation to the above question:
![v_i = v [ f_L *(v - v_b) - f_s*(v + v_b)] / [f_L * (v - v_b) + f_s*(v +v_b)]](https://tex.z-dn.net/?f=v_i%20%3D%20v%20%5B%20f_L%20%2A%28v%20-%20v_b%29%20-%20f_s%2A%28v%20%2B%20v_b%29%5D%20%2F%20%5Bf_L%20%2A%20%28v%20-%20v_b%29%20%2B%20f_s%2A%28v%20%2Bv_b%29%5D)
= v * (83.1 * (v-4.3) - 80.7 ( v+4.3))/ [83.1 *(v - 4.3) + 80.7*(v + 4.3)]
v = 344 m/s
vi = 344 * ( 83.1* (344-4.3) - 80.7*(344+4.3) ) / (83.1 *(344 - 4.3) + 80.7*(344 + 4.3))
= 0.74 m/s
The net force will point towards the acceleration of the object, as supported by Newton's second law.
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: