Question

which expression represents the tension in the string? assume an ideal string and an ideal pulley. choose 1 answer: a $m_ag$ b $m_cg$ c $(m_a + m_b + m_c)g$ d $(m_a + m_c)g$

Explanation:

Step1: Analyze the System

Assume a system with masses \( m_A \), \( m_B \), \( m_C \) connected by an ideal string and ideal pulley. For an ideal string and pulley, the tension in the string supporting the combined mass (if the system is in equilibrium or considering the total force) would relate to the total mass.

Step2: Evaluate the Options

• Option A: \( m_A g \) only considers mass \( A \), not the total system.
• Option B: \( m_C g \) only considers mass \( C \), incorrect.
• Option C: \( (m_A + m_B + m_C)g \) considers the total mass of the system. If the string is supporting all three masses (e.g., in a pulley system where the string holds the combined weight), the tension would balance the total weight.
• Option D: \( (m_A + m_C)g \) misses \( m_B \), incorrect.

Answer:

C. \((m_{\text{A}} + m_{\text{B}} + m_{\text{C}})g\)