Question

The driver of a car moving towards a rocket launching pad with a speed of $6ms^{- 1}$observed that the rocket is moving with speed of $10ms^{- 1}$. The upward speed of the rocket as seen by the stationary observer is nearly

• A. $4ms^{- 1}$
• B. $6ms^{- 1}$
• C. $8ms^{- 1}$
• D. $11ms^{- 1}$

Answer 1

Answer: (D)

$11ms^{- 1}$

Answer 2

Observed speed,

$v = \sqrt{(10)^{2} + (6)^{2}} = \sqrt{136}$

$= 11ms^{- 1}$