# How to understand parameter "relativeweight"

Dear all,

How to understand the parameter "relativeweight"?

When defining a floating body, if its value is "relativeweight=1.25", what attributes of the floating body will it affect?

Best regards!

• rho = 1000

relative weight = 1.25

actual weight = 1.25*1000

• I agree with you, but in some cases the three may not be satisfied with the above relationship. This is my XML file. You can see that the "massbody value" in line 237 is calculated to be 0.46kg instead of the expected value (0.05*0.1*0.05)*1250=0.3125kg.

By the way, does "masspart" mean the mass of each floating particle? If so, the values in the picture are not as expected.

Best regards!

• Masspart is mass of each particle per default as I remember, depending on resolution, as shown in the DualSPHysics guide.

Massbody is the total mass of all the particles in the body, in your case the equation is then:

masspart * count * relative weight = 0.001*368*1.25 = 0.46 kg

This is why when working with floating objects, just specify the mass directly, anything else is "wrong".

Double check this

Kind regards