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wr8899
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Homework Statement
Consider a rocket in space that ejects burned fuel at a speed of v_ex= 2.0 km/s with respect to the rocket. The rocket burns 10 % of its mass in 340 s (assume the burn rate is constant).
(a) What is the speed v of the rocket after a burn time of 170.0 s? (suppose that the rocket starts at rest; and enter your answer in m/s) ?
(b) What is the instantaneous acceleration of the rocket at time 170.0 s after the start of the engines?(in m/s^2 ) ?
Homework Equations
v_f = -v_ex*ln(m_final/m_initial) - g*burn time
The Attempt at a Solution
I plugged in the data, getting -2000*ln(0.95) - g*170, but got the velocity wrong. I have no idea where I went wrong, and I am stuck here, along with finding the acceleration. Can someone please help me get unstuck here. Thanks and sorry to be a bother.