Answer:
Stretching
Explanation:
Stretching is a great way to improve your flexibility!
We have the relation
where 
denotes the velocity of a body A relative to another body B; here I use B for boat, E for Earth, and R for river.
We're given speeds
Let's assume the river flows South-to-North, so that
and let 
be the angle made by the boat relative to East (i.e. -90° corresponds to due South, 0° to due East, and +90° to due North), so that
Then the velocity of the boat relative to the Earth is
The crossing is 153.0 m wide, so that for some time 
we have
which is minimized when 
so the crossing takes the minimum 30.0 s when the boat is pointing due East.
It follows that
The boat's position 
at time is
so that after 30.0 s, the boat's final position on the other side of the river is
and the boat would have traveled a total distance of
Sound waves are known to be the one that's not considered as a type of electromagnetic energy. As for microwaves and x-rays, they tend to share the same frequencies that can be considered as electromagnetic, and sound waves have a different frequency than them.
After the great 1906 San Francisco earthquake, geolophysicistHarry Fielding Reid examined the displacement of the ground surface along the San Andreas Fault. He concluded that the quake must have been the result of the elastic reboundof the strain energy in the rocks on either side of the fault.
strain energy is 0. 5x force x (compression) X (compression)
There is a lot of force and a bit of compression when rocks squash up against other rocks causing earthquakes
