Question

A jet airplane travelling at the speed of 500 km $h^{-1}$ ejects its products of combustion at the speed of 1500 km $h^{-1}$ relative to the jet plane. The speed of the products of combustion with respect to an observer on the ground is

• A. 500 km $h-1$
• B. 1000 km $h-1$
• C. 1500 km $h-1$
• D. 2000 km $h-1$

Answer 1

The correct option is B 1000 km $h-1$

${\overrightarrow{V}}_{jet}=500$ Km/hr.

${\overrightarrow{V}}_{jomb./Jet}={\overrightarrow{V}}_{comb/ground}-{\overrightarrow{V}}_{het/ground}$

$1500$ Km/hr. $=x-(-500)$ {$(-)ve$ due to direction opp to combustion]

$x=+1000$ Km/hr.

${\overrightarrow{V}}_{comb/g}=1000Km/hr$.