Answer:

Explanation:
The change in kinetic energy will be simply the difference between the final and initial kinetic energies: 
We know that the formula for the kinetic energy for an object is:

where <em>m </em>is the mass of the object and <em>v</em> its velocity.
For our case then we have:

Which for our values is:

There water has a lot of salt in it, so it would be denser. People float better when the water is denser.
Answer:1.5×10 to the power of 17(unit-Hertz/H)
Explanation:V=F×Wavelength
F=V/Wavelength=3×10 to power/2×10 to power of -9=1.5×10 to power of 17
The x and y components of the velocity vector is 17.32 m/s and 10 m/s respectively.
<h3>
What is the x - component of the velocity?</h3>
The x-component of the ball's velocity is the velocity of the ball in the horizontal direction or x-axis.
The velocity of the ball in x-direction is calculated as follows;
Vx = V cosθ
where;
- Vx is the horizontal velocity of the ball
- V is the speed of the ball
- θ is the angle of inclination of the speed
Vx = (20 m/s) x (cos 30)
Vx = 17.32 m/s
The velocity of the ball in y-direction is calculated as follows;
Vy = V sinθ
where;
- Vy is the vertical velocity of the ball
- V is the speed of the ball
- θ is the angle of inclination of the speed
Vy = 20 m/s x sin(30)
Vy = 10 m/s
Learn more about x and y components of velocity here: brainly.com/question/18090230
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