Three particles of masses 4 kg, 2 kg and 2 kg are acted upon by collinear external forces +3 N, −8 N and +4 N, respectively. Find the magnitude of centre-of-mass acceleration (m/s²).
Physics · Mixed Chapter
JEE Main Practice

Question

Three particles of masses 4 kg, 2 kg and 2 kg are acted upon by collinear external forces +3 N, −8 N and +4 N, respectively. Find the magnitude of centre-of-mass acceleration (m/s²).

G1 Physics · Accepted Answer

Step 1: Total mass M = 4+2+2 = 8 kg. Step 2: The algebraic sum of given forces is Fnet = 3−8+4 = −1 N. Step 3: Magnitude acm = |Fnet|/M = 1/8 = 0.125 m/s². Step 4: PDF prints 0.63 m/s²; this conflicts with the three stated signed forces. Do not silently accept this value.