Specific heat capacity refers to the heat capacity per mass. As you can probably imagine, it is not always useful to talk about the total heat capacity, e.g., if you want to characterize not an object, but a type of material. There is also molar heat capacity, which is the heat capacity per 1 mol particles and which is directly connected to the specific heat capacity through the molar mass of a material.
For specific impulse, it is about momentum change (which is force) per ejected unit of mass. So that isn't necessarily comparable to specific heat capacity because it does not just depend on the material that is ejected but rather by the exit velocity of the ejected material. In this case, you might also consider the volume-specific impulse, which gives you the force per ejected unit of volume, as you have limited space in a rocket.
Forty__ t1_jbjpi4w wrote
Reply to What does the word "specific" mean in a scientific context? by doodlelol
Specific heat capacity refers to the heat capacity per mass. As you can probably imagine, it is not always useful to talk about the total heat capacity, e.g., if you want to characterize not an object, but a type of material. There is also molar heat capacity, which is the heat capacity per 1 mol particles and which is directly connected to the specific heat capacity through the molar mass of a material.
For specific impulse, it is about momentum change (which is force) per ejected unit of mass. So that isn't necessarily comparable to specific heat capacity because it does not just depend on the material that is ejected but rather by the exit velocity of the ejected material. In this case, you might also consider the volume-specific impulse, which gives you the force per ejected unit of volume, as you have limited space in a rocket.