An anchored fishing boat uses sonar to work out how deep would the water be if the echo took 2 seconds to return?

a) how deep is the water
b) if the boat was on a lake instead of the sea, how deep would the water be if the echo took 2 seconds to return.

c) why is it important that the sonar machine has the information about what kind of water the boat is in.

d) a little while later, the ultrasound machine detects two echoes from a ping, after 0.05 seconds and 0.7 seconds. suggest what these echoes mean..

i need the right answers for today

Avery long solenoid of inner radius 2.75 cm creates an oscillating magnetic field of the form = for this solenoid, =0.00425 t and =319 rad/s. (a)what is the maximum value of the induced electric field at a perpendicular distance 1.45 cm from the axis of the solenoid? (b) what is the maximum value of the inducted electric field at a point 5.85 cm perpendicular from the axis of the solenoid?

Cells in the nervous system have a potential difference of 70 mv across the cell membrane separating the interior of the cell from the extracellular fluid. this potential difference is maintained by ion pumps that move charged ions across the membrane. is this an emf? select the correct answer and explanation. 1)no. the ion pumps cannot separate charges; thus, they cannot create a potential difference. 2)yes. the ion pumps cannot separate charges, but they still can create a potential difference. 3)yes. the ion pumps can actively separate charge; thus, they can create a potential difference. 4)no. the ion pumps can separate charges, but they cannot create a potential difference.

Acorporation gives out its profits as dividends paid to whom?