Answer: (d)
Explanation:
Given
Mass of the first ram 
The velocity of this ram is 
Mass of the second ram 
The velocity of this ram 
They combined after the collision
Conserving the momentum
![\Rightarrow m_1v_1+m_2v_2=(m_1+m_2)v\\\Rightarrow 49\times (-7)+52\times (9)=(52+49)v\\\Rightarrow v=\dfrac{125}{101}\ m/s \quad[\text{east}]](https://tex.z-dn.net/?f=%5CRightarrow%20m_1v_1%2Bm_2v_2%3D%28m_1%2Bm_2%29v%5C%5C%5CRightarrow%2049%5Ctimes%20%28-7%29%2B52%5Ctimes%20%289%29%3D%2852%2B49%29v%5C%5C%5CRightarrow%20v%3D%5Cdfrac%7B125%7D%7B101%7D%5C%20m%2Fs%20%5Cquad%5B%5Ctext%7Beast%7D%5D)
Momentum after the collision will be

Therefore, option (d) is correct
Ans: Beat Frequency = 1.97HzExplanation:
The fundamental frequency on a vibrating string is

<span> -- (A)</span>
<span>here, T=Tension in the string=56.7N,
L=Length of the string=0.66m,
m= mass = 8.3x10^-4kg/m * 0.66m = 5.48x10^-4kg </span>
Plug in the values in Equation (A)
<span>so </span>

<span> = 197.97Hz </span>
<span>the beat frequency is the difference between these two frequencies, therefore:
Beat frequency = 197.97 - 196.0 = 1.97Hz
-i</span>