A 2 kg block lies on a lorry accelerating at 8 m/s². Coefficients of static and kinetic friction are 0.9 and 0.7, with g=10 m/s². Find block's ground-frame acceleration (m/s²).
Physics · Mixed Chapter
JEE Main Practice

Question

A 2 kg block lies on a lorry accelerating at 8 m/s². Coefficients of static and kinetic friction are 0.9 and 0.7, with g=10 m/s². Find block's ground-frame acceleration (m/s²).

G1 Physics · Accepted Answer

Step 1: Acceleration required to prevent sliding is 8 m/s². Step 2: Maximum available static-friction acceleration μₛg=0.9×10=9 m/s². Step 3: Since 8<9, static friction is sufficient and the block does not slip. Step 4: Block accelerates with the lorry: 8 m/s².