Answer:
2 seconds
Explanation:
The frequency of a wave is related to its wavelength and speed by the equation

where
f is the frequency
v is the speed of the wave
is the wavelength
For the wave in this problem,
v = 2 m/s

So the frequency is

The period of a wave is equal to the reciprocal of the frequency, so for this wave:

This means that the wave takes 4 seconds to complete one full cycle.
Therefore, the time taken for the wave to go from a point with displacement +A to a point with displacement -A is half the period, therefore for this wave:

The answer is 15.0N its explained in newtons third law hope this helps:)
You will need to multiply them.
I have physics class and for acceleration we use 9.8m/s^2 but you used 9.5m/s^2.
If that’s what ur teacher wants u to use that’s ok. But yeah you multiply them.
F=ma
You multiply m and a