Question

the system shown in the following figure is balance. what is the torque created by the 50 g mass?
options: 9 n·m, 900 n·m, 9,000 n·m, 0.09 n·m

Explanation:

Step1: Convert mass to kg

Mass \( m = 50\ \text{g} = 0.05\ \text{kg} \) (since \( 1\ \text{kg} = 1000\ \text{g} \))

Step2: Calculate force (weight)

Force \( F = mg \), where \( g = 9.8\ \text{m/s}^2 \approx 10\ \text{m/s}^2 \) for approximation. So \( F = 0.05\ \text{kg} \times 10\ \text{m/s}^2 = 0.5\ \text{N} \)

Step3: Convert distance to meters

Distance \( d = 18\ \text{cm} = 0.18\ \text{m} \) (since \( 1\ \text{m} = 100\ \text{cm} \))

Step4: Calculate torque

Torque \( \tau = F \times d = 0.5\ \text{N} \times 0.18\ \text{m} = 0.09\ \text{N·m} \) (using \( g = 9.8 \) would be \( 0.05\times9.8\times0.18 = 0.0882 \approx 0.09 \))

Answer:

0.09 N·m