Final answer:
The mass of the metal can be calculated by dividing the weight by the acceleration due to gravity. Given the weight is 3.0 N and using the standard gravity of 9.8 m/s^2, the mass is 0.306 kg, rounded to one significant figure, which is 0.3 kg.
Step-by-step explanation:
To calculate the mass of a piece of metal given its weight, you can use the relationship between mass (m), gravity (g), and weight (W): W = m × g. In this case, the weight of the metal is given as 3.0 N (newtons). Assuming the acceleration due to gravity (g) as 9.8 m/s2, which is approximately the Earth's standard gravity, you can rearrange the formula to solve for mass (m = W/g).
Using those values:
m = W/g = 3.0 N / 9.8 m/s2 = 0.306 kg
Since the question asks for the answer to one significant figure, the mass of the metal can be reported as 0.3 kg. Therefore, the correct answer to the question is a) mass = 0.3 kg.