Question

A block A is made to move over an inclined plane of inclination q with constant acceleration a₀ as shown in figure. Initially bob B hanging from block A is held vertical. Magnitude of acceleration of block A relative to bob immediately after bob is released is –

• A. a₀
• B. a₀ sinq
• C. a₀ cosq
• D. (a₀ – g sinq)

Answer 1

Answer: (C)

a₀ cosq

Answer 2

$\overrightarrow { \mathrm { a } } _ { \mathrm { AG } }$ = a₀ $\cos \theta \hat { i }$ + a₀ sinq $\hat { \mathrm { j } }$

$\overrightarrow { \mathrm { a } } _ { \mathrm { BG } } = \mathrm { a } _ { 0 } \sin \theta \hat { \mathrm { j } }$

$\therefore \overrightarrow { \mathrm { a } } _ { \mathrm { AB } } = \mathrm { a } _ { 0 } \cos \theta \hat { \mathrm { i } }$