Question

Imagine a landing craft approaching the surface of Callisto, one of Jupiter's moons. If the engine provides an upward force (thrust) of 2880 N, the craft descends at constant speed; if the engine provides only 1944 N, the craft accelerates downward at 0.39 m/s2. What is the weight of the landing craft in the vicinity of Callisto's surface?

Answer 1

Answer:

Weight:$W=2880N$

Mass:$m=2400kg$

Explanation:

If the craft descends at constant speed it means that the engine thrust equals the gravitational force of the craft as the acceleration equals zero, from Newton´s second law:

$F=(Thrust1-W)=m*a=0 => Thrust1=W=2880N$

Where W is the weight of the craft.

For the second case with lower thrust:

$F=W-Thrust2=m*a=m*0,39 m/s^{2}$

$m=\frac{W-Thrust2}{0,39 m/s^{2}} =\frac{2880N-1944N}{0,39 m/s^{2}} = 2400kg$