Answer:
Time, t = 0.104 seconds
Explanation:
Frequency of the click of the Dolphin, f = 55.3 kHz
A dolphin sends out a series of clicks that are reflected back from the bottom of the ocean 80 m below, d = 80 m
The speed of sound in seawater is, v = 1530 m/s
Once the sound is send and reflects, the total distance covered by it is 2d such that,

So, the time elapses before the dolphin hears the echoes of the clicks is 0.104 seconds.
The special feature of the upper mantle is the asthenosphere.It is located just below the lithosphere and is made up of rocks that is fluid and can move.The fluidity of these rocks powered the movement of the tectonic plates on the earths crust.Circular convection cycles in the hot,fluid upper mantle rock move the plates over the surface of the earth.
Answer:
Yes , insulation has no role
The ball rises for v/g seconds; which equals 14.7/9.8=1.5 seconds . After this time, it’s height will be:
h(t)=g/2(1.5)²+14.7(1.5)
=-4.9 x 2.25 + 22.05
=11.025m
The ball then falls for 49+11.025=60.025m, which takes:
g/2t²=60.025
t²=12.25
t=3.5 secs
Total time: 1.5+3.5=5 seconds
Answer:
The correct option is (a).
Explanation:
We know that, the E is inversely proportional to the distance as follows :

We can write it as follows :

Put all the values,

So, the correct option is (a).