# Thread: Help with Mechanics Elasticity question?

1. ## Help with Mechanics Elasticity question?

Two light elastic strings each have natural length 24 cm. One end of each string is attached to a particle P of mass 0.6 kg, and the other ends are attached to two points A and B on a horizontal beam, where AB = 48 cm. The particle hangs in equilibrium, at a distance 10 cm vertically below the beam.

Find the value of the modulus of elasticity

i think modulus of elasticity = (tension x natural length) / extention

2. Originally Posted by mayawrite
Two light elastic strings each have natural length 24 cm. One end of each string is attached to a particle P of mass 0.6 kg, and the other ends are attached to two points A and B on a horizontal beam, where AB = 48 cm. The particle hangs in equilibrium, at a distance 10 cm vertically below the beam.

Find the value of the modulus of elasticity

i think modulus of elasticity = (tension x natural length) / extention
Start by finding the extension (draw a diagram and use Pythagoras's theorem to find the stretched length of the strings).

Now resolve the tension in one of the strings into vertical and horizontal components, and as the tension in the two strings is equal twice the vertical component of tension equals in magnitude the gravitational force on the mass.

CB