Question
c o secure https://session.masteringphysics.com/myctitermView?assignmentProblemlDz791 27483 Homework Problem 9.83 Problem 9.83 Part A altnude of e3n m/s althude of 6350 km fires its rockets, which eject gas at a speed of 1450 m/s (relative to the rocket). A rocket traveling 1750 m/'s away from the Earth at an If the mass of the rocket at this moment is 2.40*104 kg and an acceleration of 2.0 m/s' is desired, at what rate must the gases be ejected? Express your answer using two significant figures . 188 kg/s My Answers Give Up Incorrect; Try Again; 7 attempts remaining 5 3 caps lock commandoption command control option
Explanation / Answer
gravitaional accleration at 6350 altitude
g' = g(Re/R)^2
R = Re+h
Re = 6400 km ( radius of earth )
h = 6350 km
g' = 2.469 = 2.47 m/s^2
total acceleration = 2.47 +2 = 4.47 m/s^2
F = ma = 2.4 x 10^4 * 4.47 = 1.07 x 10^5 N
F = dp/dt
p = mv
F = (dm/dt)*v
dm/dt = F/v
dm/dt = F/1450 = 73.97 kg/s = 74 kg/s