Question Detail

PHY 101 PHY 101 Past Questions Objective Question

Question

A uniform beam has length 8 m and mass 60 kg. It is suspended in a horizontal position by two ropes as shown. Find the tension in each rope. (Ropes at 1 m from left end and 2 m from right end)
Options
A 240 N, 360 N
Correct Answer
B 15 N, 35 N
C 24 N, 75 N
D 25 N, 16 N
Correct Answer

Option A is the correct answer.

Detailed Explanation

Beam weight = 60 × 9.8 = 588 N. Let T₁ be left rope at 1 m from left, T₂ be right rope at 6 m from left (since 8 m total, 2 m from right means at 6 m from left). Taking moments about left end: Clockwise moment from weight at center (4 m) = 588 × 4 = 2352 Nm. Anticlockwise moments: T₂ at 6 m gives 6T₂. So 6T₂ = 2352 → T₂ = 392 N. Then T₁ = 588 - 392 = 196 N. Not matching options. If g=10, weight=600 N, then 6T₂ = 600×4=2400, T₂=400 N, T₁=200 N. Option A is 240 N, 360 N, sum=600 N, but positions would be different. If ropes at 1 m and 5 m? Then moments: T₂ at 5 m: 5T₂ = 600×4=2400, T₂=480 N, T₁=120 N. Not matching. Possibly the diagram shows different positions.

Hint

Use equilibrium conditions: sum of forces = 0, sum of moments = 0.

Question Info