The dolphin would send an underwater message because the water is denser than air and therefore the sound would be louder and would travel faster. The denser the object the faster the sound travels.
Answer: v = 4.4 m/s
Explanation:
In the absence of friction, the total mechanical energy will be constant
KE₀ + PE₀ = KE₁ + PE₁
0 + mg(6) = ½mv₁² + mg(5)
½mv₁² = mg(6 - 5)
v = √(2g(1)) = 4.4 m/s
Answer:

Explanation:
Given that,
A radio wave transmits 38.5 W/m² of power per unit area.
A flat surface of area A is perpendicular to the direction of propagation of the wave.
We need to find the radiation pressure on it. It is given by the formula as follows :

Where
c is speed of light
Putting all the values, we get :

So, the radiation pressure is
.