Resultant is the correct answer!
Answer:
Hey there
Where trying to say that:
Newton's first law gives the concept of force and momentum?
That's false if that's is what you said.
Newton's first law tells us that objects in motion will remain in motion and objects at rest will remain at rest.
Newton's second law gives us the concept of force and momentum.
Initially, the velocity vector is 
. At the same height, the x-value of the vector will be the same, and the y-value will be opposite (assuming no air resistance). Assuming perfect reflection off the ground, the velocity vector is the same. After 0.2 seconds at 9.8 seconds, the y-value has decreased by 
, so the velocity is 
.
Converting back to direction and magnitude, we get 
The correct answer is (b.) y/x hertz. That is because the formula to get the frequency is f = v / w. The following values (v=y meters / second; wavelength = x meters) must be substituted to the equation, which leaves you y/x hertz.
