<span>When two waves of same frequency travel in a medium simultaneously in the same direction then, due to their superposition, the resultant intensity at any point of the medium is different from the sum of intensities of the two waves. At certain points the intensity of the resultant wave has a large value while at some points it has a very small or zero. This is called wave interference.</span>
Answer:
Explanation:
Given
length of rope 
velocity while running 
when the person jumps off the bank and hang on the rope then we can treat the person as pendulum with Time period T which is given by




Greatest Possible distance will be covered when person reaches the other extreme end of assumed pendulum (velocity=zero)
therefore he must hang on for 0.5 T time

"1 watt" means 1 joule of energy per second.
75 W means 75 joules/sec .
Energy = (75 Joule/sec) x (12 min) x (60 sec/min)
Energy = (75 x 12 x 60) (Joule-<em>min-sec</em> / <em>sec-min</em>)
<em>Energy = 54,000 Joules</em>
20Ah is the number of charge that can be supplied at 20A for 1 hour. If you wish to drain it in 19 minutes, then the current is:

The final speed of the car at the given conditions is 30.1 m/s.
The given parameters:
- <em>Mass of the car, m = 1700 kg</em>
- <em>Velocity of the car, v = 21 m/s</em>
- <em>Time of motion, t = 10 s</em>
- <em>Additional energy provided by the engine, E₁ = 22,000 J</em>
- <em>Energy used in overcoming friction, E₂ = 3,666.67 J</em>
The change in the energy applied to the car is calculated as;

The final speed of the car is calculated as follows;

Thus, the final speed of the car at the given conditions is 30.1 m/s.
Learn more about change in kinetic energy here: brainly.com/question/6480366