Okay, so this is probably very easy, just checking the solution

[Adama0905]

Homework Statement

Okay guys, I'm new here, and this problem just annoyed me because I believe it's very simple, but it looks like it could be more complicated.

Two large crates, with masses 640 kg and 490 kg, are connected by a stiff, massless spring (k=8.1 kN/m) and propelled along an essentially frictionless, level factory floor by a force applied horizontally to the more massive crate. If the spring compresses 5.1 cm from its equilibrium length, what is the applied force?

Homework Equations

I think it's just this one: Fspring = -k*x

The Attempt at a Solution

Okay, the only thing that makes it sound at all complicated is that the crates are different masses, and that they talk about mass at all. But I want to say it's just 8.1*(.051) to get kN. Is that it? Or should I take into account the masses of the boxes. In which case I'm not quite sure where to go.

 

[Gear300]

Looks like you got it.

 

[tomcue]

Hi there! I can confirm that your approach is correct. The mass of the crates does not affect the calculation of the applied force, as the spring is connected to both crates and will exert the same force on each of them. So, the only relevant factor in this problem is the stiffness of the spring, which is represented by the spring constant (k). Therefore, your calculation of Fspring = -k*x is the correct equation to use. Keep up the good work!