Final answer:
The force of gravity on the washers is already provided in newtons, which are the product of mass and the acceleration of gravity (9.80 m/s²), so the values given are the forces of gravity for each number of washers. So, the correct option is B) 2 washers: 9.8 N
Step-by-step explanation:
To calculate the force of gravity on the washers given their mass in grams, one can use the formula for weight (W), where W = mg (mass times the acceleration due to gravity).
The question provides the force in newtons (N), which implies that the mass (m) of the washers has already been accounted for and multiplied by the acceleration due to gravity (g = 9.80 m/s² on Earth).
Therefore, if we have the masses (1 washer: 4.9 N, 2 washers: 9.8 N, 3 washers: 14.7 N, 4 washers: 19.6 N), these already represent the force of gravity acting on each set of washers.
Therefore, the correct option is B) 2 washers: 9.8 N