1.renewable energy
2.renewable energy
3.Turning off the lights when you are not in a room
4.conservation of energy
5.Driving an SUV
6.stored energy
7.Always from one side to another
8.use our energy resources wisely
9.conservation of energy
10.by either moving liquids or moving air currrents
11.potential energy
12.radiation
13.insulators
14.radiation
15.Evaporation
16.Thermal energy moves to an object with less heat.
17.Burning your finger on a hot match
18.potential energy
19.Energy is never being created or destroyed.
20.touching each other
<span>The rate of change in velocity is acceleration.</span>
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!