Q69. A scaffold that weighs 400 N supports two painters, one 500 N and the other 400 N. The reading in the left scale is 800 N. What is the reading in the right-hand scale?

Background

Topic: Forces and Mechanical Equilibrium

This question tests your understanding of force balance and equilibrium in a system. Specifically, it involves calculating the support forces (tensions) in the ropes holding up a scaffold with known weights.

Key Terms and Formulas

• Mechanical Equilibrium: When the sum of all forces acting on a system is zero ().

• Support Force: The upward force provided by a scale or rope to balance the downward force of weight.

• Weight: The force due to gravity, (here, given directly in Newtons).

• Equilibrium Rule:

Step-by-Step Guidance

1. Identify all the forces acting on the scaffold: the weights of the scaffold (400 N), the two painters (500 N and 400 N), and the upward forces from the left and right scales.

2. Write the equilibrium equation for vertical forces: , or .

3. Plug in the known values: , , , .

4. Set up the equation to solve for the unknown right scale reading: .

5. Now, rearrange the equation to isolate and prepare to solve for its value.

Try solving on your own before revealing the answer!