Answer:
40%
Explanation:
Calculate the percent of the mass that is carbon:

The correct answer is particle pollution.
MA= output force/ input force
MA= 100N/20N
MA= 50
If the cube is 3 cm on each side, then it has a volume of 27 cm^3 (3 x 3 x 3). Density is mass divided by volume, so its density is 72.9/27 = 2.7 g/cm^3.
<span>Going by the density, the cube is made of Aluminium - density is a fairly unique quantity</span>