As a rocket is fired from a launching pad, its speed and acceleration increase with time as its engines continue to operate. Explain why this occurs even though the thrust of the engines remains constant.
2007-09-27 09:06:40 · 3 answers · asked by back2back 2 in Science & Mathematics ➔ Physics
F= m x a
thrust is a force and if it is constant, then if m decreases, a must increase. m does decrease as fuel burns off.
since a is positive and increasing, and since a = dv/dt , dv/dt must be positive. ie (v2 -v1) / t = positive. therefore, v2>v1. ie velocity is increasing
fyi,
weight of space shuttle + boosters + fuel tank at liftoff = 2.1 x 10^6 kg
weight of fuel = 1.8 x 10^6 kg
that's 87% of the weight of the space shuttle at liftoff is fuel....
2007-09-27 09:16:44 · answer #1 · answered by Dr W 7 · 1⤊ 0⤋
As fuel is consumed the mass of the rocket decreases:
f = ma
If you decrease m , a increases.
2007-09-27 16:15:04 · answer #2 · answered by jsardi56 7 · 0⤊ 0⤋
Fuel is used up, fed evenly...
2007-09-27 16:13:06 · answer #3 · answered by hmata3 3 · 0⤊ 1⤋