What is the mass of the object?

Question

An object attached to a spring is pulled across a horizontal frictionless surface. If the force constant (spring constant) of the spring is 41 N/m and the spring is stretched by 0.43 m when the object is accelerating at 1.1 m/s^2.

Answer 1

F = ma

What are the forces acting on the object? Since the surface is frictionless, the only force is that from the spring. What is that force? Well, for a spring, the magnitude of the force is kx (spring constant times distance stretched). From the problem, k = 41 N/m and x = 0.43 m.

Once you have the force, then m = F/a with a = 1.1 m/s^2