Question

If a coin is put in the bottom of a vessel filled with liquid upto a height 10 cm. If whole vessel moves down at 3 m/s. The velocity of coin as observed by an eye at rest will be –

• A. 4 m/s
• B. 3 m/s
• C. $\frac { 9 } { 4 }$ m/s
• D. None of these

Answer 1

Answer: (B)

3 m/s

Answer 2

$\frac { \mathrm { d } _ { \text {observer } } } { 1 } = \frac { \mathrm { h } } { 1 } + \frac { 10 } { \mathrm { r } }$

v_observer = $\frac { \mathrm { dh } } { \mathrm { dt } }$ = 3m/s