Question

# Two objects are said to be in parallel when they both act on the system in...

Two objects are said to be in parallel when they both act on the system in the same way, e.g., two forces are in parallel if they have the same direction and are applied at the same point.

A light rod of length 33.7 cm is held aloft from the ceiling by two springs attached to its ends. The left spring has a stiffness of 15.3 kg/s2 and equilibrium length of 29.5 cm and the right spring has a stiffness of 17.9 kg/s2 and equilibrium length of 30.4 cm. A ring weighing 549 g is placed 23.3 cm from the left spring.

(a) How much does the left spring stretch?

(b) How much does the right spring stretch?

Now, mathematically slide the ring to the point that levels the rod.

(c) At what distance from the left spring should you place the ring in order for the rod to be level?

(d) How far from the ceiling is the rod when it's level?

Now consider modelling the two springs as if there were only one spring that held the ring aloft.

(e) What is the equilibrium length of the spring?

(f) How much does the spring stretch when the ring is placed on it?

(g) What is the stiffness of the spring?