Laws of Motion - Result Question 17

«««< HEAD:content/english/neet-pyq-chapterwise/physics/laws-of-motion/laws-of-motion-result-question-17.md

17. A $600 kg$ rocket is set for a vertical firing. If the exhaust speed is $1000 ms^{-1}$, the mass of the gas ejected per second to supply the thrust needed to overcome the weight of rocket is

======= ####17. A $600 kg$ rocket is set for a vertical firing. If the exhaust speed is $1000 ms^{-1}$, the mass of the gas ejected per second to supply the thrust needed to overcome the weight of rocket is

3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/laws-of-motion/laws-of-motion—result-question-17.md (a) $117.6 kg s^{-1}$

(b) $58.6 kg s^{-1}$

(c) $6 kg s^{-1}$

(d) $76.4 kg s^{-1}$

[1990]

Show Answer

Answer:

Correct Answer: 17. (c)

Solution:

  1. (c) Thrust = weight

$\Rightarrow \frac{u d M}{d t}=m g \Rightarrow \frac{d M}{d t}=\frac{m g}{u}$

$=\frac{600 \times 10}{1000}=6 kg s^{-1}$