Final answer:
To find the work done, we use the formula Work (W) = Force (F) × Displacement (d). The force equals the weight of the mass, and after calculating, we get 1.2 J or answer choice B for the work done.
Step-by-step explanation:
To find the work done when a 0.4 kg mass suspended from a wire causes it to stretch by 3 mm, we can use the formula for work, which is Work (W) = Force (F) × Displacement (d). The force exerted by the mass is equal to its weight, which can be calculated using the equation Weight (F) = mass (m) × gravitational acceleration (g), where g is approximately 9.8 m/s2.
The weight of the mass is thus 0.4 kg × 9.8 m/s2 = 3.92 N (newtons). Since the displacement is given in millimeters, we convert it to meters by dividing by 1000, resulting in 0.003 m. Finally, the work done is calculated: Work (W) = 3.92 N × 0.003 m = 0.01176 J, which can be rounded to 0.012 J or 1.2 J, as energy is usually given to two significant figures.