Answer:
A. when the mass has a displacement of zero
Explanation:
The velocity of a mass on a spring can be calculated by using the law of conservation of energy. In fact, the total energy of the mass-spring system is equal to the sum of the elastic potential energy (U) of the spring and the kinetic energy (K) of the mass:

where
k is the spring constant
x is the displacement of the mass with respect to the equilibrium position of the spring
m is the mass
v is the velocity of the mass
Since the total energy E must remain constant, we can notice the following:
- When the displacement is zero (x=0), the velocity must be maximum, because U=0 so K is maximum
- When the displacement is maximum, the velocity must be minimum (zero), because U is maximum and K=0
Based on these observations, we can conclude that the velocity of the mass is at its maximum value when the displacement is zero, so the correct option is A.
The horizontal displacement of a projectile launched at an angle
Answer:
North of west
Explanation:
Given
Plane wishes to fly in west
but wind with speed 33.9 km/h towards south obstructing its path
so plane must fly at an angle of \theta w.r.t west such that it final velocity is towards west
Plane absolute speed=195 km/h
To fly towards west velocity in Y direction should be zero
thus 

so Plane should head towards
North of west in order to fly in west.
So plane
actual velocity is

I think you forgot to give the choices along with the question. I am answering the question based on my research and knowledge. <span>If a layer was deposited but does not appear in the rock record, the thing that happened is erosion. I hope that this is the ans wer that has actually come to your desired help.</span>
The trip from Camp Wood to the Pacific
Ocean and back again took 1.5 years to complete.<span>
</span>
<span>The </span>Lewis<span> and Clark </span>Expedition<span> from May 1804 to September 1806, also known as
the Corps of Discovery </span>Expedition, was the first
American expedition<span> to
cross what is now the western portion of the United States.</span>