(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A spacecraft descends vertically near the surface of Planet X. An upward thrust of 25.0kN from its engines slows it down at a rate of 1.20m/s^2, but if an upward thrust of only 10.0kN is applied, it speeds it up at a rate of .80m/s^2. Apply Newton's second law to each case, speeding up or slowing down, and use this to find the spacecraft's weight near the surface of Planet X.

2. Relevant equations

F = ma

3. The attempt at a solution

Okay, I'm confused about how if 25.0kN force is applied, then it slows down but 10.0kN part will speed it up. I guess maybe that's why my method is wrong and I keep getting the wrong answer. This is what I'm doing: since I have the force and acceleration, I converted kN to N and divided by its acceleration to find the mass. Then I take the mass x gravity = weight, converting it back kN. Pls help me, where did I go wrong?

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Force Acceleration Weight

**Physics Forums | Science Articles, Homework Help, Discussion**