How Much Force Compresses a Spring Between Two Crates on a Frictionless Surface?

[saman_b21]

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?

 

[Doc Al]

What force does the spring exert? What forces act on the smaller mass? What's its acceleration?

 

[Vijay Bhatnagar]

Determine acceleration of the two masses (Applied force/Total mass). This will be the acceleration of each mass. Consider the smaller mass alone. Force acting on it is due to the restoring force of the spring, which is equal to kx. Write equation : Force = mass x acceleration for the smaller mass (acceleration a is in terms of the applied force F). Solve for F.

 

[saman_b21]

Determine acceleration of the two masses (Applied force/Total mass). This will be the acceleration of each mass. Consider the smaller mass alone. Force acting on it is due to the restoring force of the spring, which is equal to kx. Write equation : Force = mass x acceleration for the smaller mass (acceleration a is in terms of the applied force F). Solve for F.

thanks man i got the answer.