Simple Physics concepts

Hello......

    I have a small doubt. It may feel silly, but please reply.. 

   Suppose I have a pendulum and it is impacting onto a structure. The mass of pendulum is 'm' and the intiial velocity is 'v'. The condition is that the KE at the time of impact should be 'E'. E= 0.5*m*v2 . 

  Now i change the mass of the pendulum to m1 correspondingly velocity should be changed to v1 so that E1=E.

 Now i need to compare the force transmitted to the structure. F = ma. 

 I found from simulation that Force transmitted is same in both cases.. How to explain this ???