SATHEE: Laws Of Motion Question 298

Laws Of Motion Question 298

Question: A 5000 kg rocket is set for vertical firing. The exhaust speed is $800 m s^{- 1}$ . To give an initial upward acceleration of $20 m s^{- 2}$ , the amount of gas ejected per second to supply the needed thrust will be $(g = 10 m s^{- 2})$

Options:

A) $127.5 k g s^{- 1}$

B) $187.5 k g s^{- 1}$

C) $185.5 k g s^{- 1}$

D) $137.5 k g s^{- 1}$

Show Answer

Answer:

Correct Answer: B

Solution:

[b] Given: Mass of rocket $(m) = 5000 k g$

Exhaust speed $(v) = 800 m / s$ Acceleration of rocket $(a) = 20 m / s^{2}$

Gravitational acceleration $(g) = 10 m / s^{2}$

We know that upward force $F = m (g + a) = 5000 (10 + 20) = 5000 \times 30$

$= 150000 N$

We also know that amount of gas ejected $(\frac{d m}{d t}) = \frac{F}{v} = \frac{150000}{800} = 187.5 k g / s^{- 1}$

Laws Of Motion Question 298

Question: A 5000 kg rocket is set for vertical firing. The exhaust speed is $800 m s^{- 1}$ . To give an initial upward acceleration of $20 m s^{- 2}$ , the amount of gas ejected per second to supply the needed thrust will be $(g = 10 m s^{- 2})$

Options:

Answer:

Solution:

Engineering Preparation

Medical Preparation

NCERT Books & Solutions

Important Resources

Other Resources

Syllabus

Test Platform

Sample Mock Test

Mentorship

NCERT Exercise Video Solution

Laws Of Motion Question 298

Question: A 5000 kg rocket is set for vertical firing. The exhaust speed is800ms−1 . To give an initial upward acceleration of20ms−2 , the amount of gas ejected per second to supply the needed thrust will be (g=10ms−2)

Options:

Answer:

Solution:

Engineering Preparation

Medical Preparation

NCERT Books & Solutions

Important Resources

Other Resources

Syllabus

Test Platform

Sample Mock Test

Mentorship

NCERT Exercise Video Solution

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Question: A 5000 kg rocket is set for vertical firing. The exhaust speed is $800 m s^{- 1}$ . To give an initial upward acceleration of $20 m s^{- 2}$ , the amount of gas ejected per second to supply the needed thrust will be $(g = 10 m s^{- 2})$