An object, whose mass is0.580kg, is attached to a spring with a force constant of144N/m. The object rests upon a frictionless, horizontal surface (shown in the figure below).

An object labeledmis attached to the right end of a horizontal spring, and the left end of the spring is attached to a wall. The spring is stretched horizontally such that the object is displaced by a distanceAto the right of its equilibrium position.

The object is pulled to the right a distanceA=0.140m from its equilibrium position (the vertical dashed line) and held motionless. The object is then released from rest.

(a)

At the instant of release, what is the magnitude of the spring force (in N) acting upon the object?

N

(b)

At that very instant, what is the magnitude of the object's acceleration (in m/s²)?

m/s²