Answer:
the ans is D... good luck
Frequency = velocity/wavelength
Frequency = 10/20
Frequency = 0.5 Hz
<span>Our equation 1 would be
m*v=M*V1+m*V2
v=V1+V2
v-V1=V2
the equation 2 would look like this
</span>V^2=V1^2+V2^2
V^2-V1^2=V2^2
(V-V1)*(V+V1)=V2^2Dividing with the 1
V+V1=V2
Velocity and time inceases