The work done to pull the sister back on the swing is equal to the increase in potential energy of the sister:
(1)
where m is the sister's mass, g is the gravitational acceleration and
is the increase in altitude of the sister with respect to its initial position.
By calling
the angle of the chain with respect to the vertical, the increase in altitude is given by
(2)
where L is the length of the chain.
Putting (2) inside (1), we find
from which we can find the mass of the sister:
If you are talking about ocean waves crashing into each other, they would probably mostly cancel out with just a bit of motion left over. If you are talking about things like frequency and amplitude, overlapping waves would combine and amplify or suppress each other, depending on their direction, position, frequency and amplitude. If the two waves complement each other, they amplify; if they conflict with each other, they are suppressed.
The resultant vector is 11√2 km due north east.
<h3><u>Explanation:</u></h3>
The vector is a type of quantity which has both magnitude and direction. This quantities when expressed needs to specify both magnitude and direction.
We need to calculate the magnitude and direction separately.
Here firstly for the magnitude,
The magnitudes are both 11 km and they are at right angles to each other.
So, the resultant magnitude = √(11² +11²) km
=11√2 km
Now for the direction, one vector is due north and the other is due east.
So the resultant vector is due north east.
So the final vector is 11√2 km due North-East.
