(I)
firstly , we will find maximum and minimum y-value
we can see that
maximum value is 5
minimum value is -5
so, we can find amplitude
![A=(5-(-5))/(2)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/25nyn3930xeijcdnbiog5itoxu698f3vgj.png)
..........Answer
(II)
we know that
wave length is the length of one wave
we can see that from B to F , there is one wave
and we are given it's length as 20cm
so, wavelength is 20cm......Answer
(III)
we know that
![velocity=wavelength*frquency](https://img.qammunity.org/2019/formulas/mathematics/middle-school/n1t52ll7idgywmnydz4ntxmbaeggh9fmyg.png)
we are given
frequency =100hz
wavelength =20cm
now, we can find velocity
![velocity=20*100cm/sec](https://img.qammunity.org/2019/formulas/mathematics/middle-school/htfycpf03a8majhl5ylc7uy61gbewzpq9d.png)
............Answer