A2L Item 098

• Description: Identify the tension in one of two strings of unequal length that are supporting a uniform rod.
• Goal: Reasoning with forces
• Source: UMPERG-ctqpe154
• Keywords: Mechanics, Tension, Torque

---

The question for students:

A uniform rod of length 4L, mass M, is suspended by two thin strings, lengths L and 2L as shown. What is the tension in the string at the left end of the rod?

1. Mg
2. Mg/2
3. Mg/3
4. Mg/4
5. None of the above

---

Commentary for teachers:

Answer

(2) For many this is straightforward but a few students are confused about the effect of the unequal lengths of string.

---