Question

question 3.
a rocket has a mass flow rate of 28,000 kg/s and an exhaust velocity of 3,200 m/s. what is the thrust force?
a. 48,000,000 n
b. 89,600,000 n
c. 50,400,000 n
d. 52,800,000 n

Explanation:

Step1: Recall the thrust formula

Thrust force \(F = v\times\frac{dm}{dt}\), where \(v\) is the exhaust velocity and \(\frac{dm}{dt}\) is the mass - flow rate.

Step2: Substitute the given values

Given \(\frac{dm}{dt}=28000\space kg/s\) and \(v = 3200\space m/s\). Then \(F=3200\times28000\).
Calculate \(3200\times28000=(3000 + 200)\times28000=3000\times28000+200\times28000\)
\(3000\times28000 = 84000000\) and \(200\times28000=5600000\)
\(F=84000000 + 5600000=89600000\space N\)

Answer:

B. \(89,600,000\space N\)