The mass of an object is a measure of its inertia, or resistance to being accelerated. The more mass an object has, the more force is required to accelerate it. The mass of an object is also equal to the amount of energy it contains, as measured by its rest energy.
The mass of grass can vary depending on the type of grass, the amount of water it contains, and other factors. However, on average, the mass of grass is about 1,000 kilograms per cubic meter. This means that a cubic meter of grass would weigh 1,000 kilograms, or about 2,200 pounds.