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

Weight:
`W=2880N`

Mass:
`m=2400kg`

Step-by-step 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=(W-Thrust2)/(0,39 m/s^(2)) =(2880N-1944N)/(0,39 m/s^(2)) = 2400kg`