Answer:
300m/s
Explanation:
velocity = frequency(wavelength)
Since 10 waves pass a point each second, frequency is 10
therefore, speed = (10)(30 = 300m/s
Water must absorb energy in order to melt, evaporate, or get warmer.
The time taken by the swimmer was 1 hour.
Why?
Since the swimmer is maintaining an angle of 150° while he was swimming, there were two components of the speed (horizontal and vertical). If we want to calculate the time taken by him to cross the river, we need to calculate the vertical speed and consider that the flow's speed is compensated by his horizontal speed.
We can calculate both components of the speed using the following formula:

Now, calculating we have:

Therefore, we have that the horizontal speed is compesating the flow's speed while his vertical speed is used to cross the river which is 1 Km wide.
Hence, we have that the tame taken is:

Have a nice day!
Answer:
The solution becomes more acidic.
Explanation:
As the pH of a solution decreases, the concentration of hydrogen ions [H+] increases. Acidic solutions have a higher concentration of hydrogen ions and a lower pH.
I hope this helped. :)
It is said to be concave
and convex is the one reflecting outward