An elastic string of length 40cm is stretch 8.0cm by a force of 14n. What will be the total length of the string when it is used to support a hanging mass of 5kg (g=9.8m/s2)

Answer 1

We can use Hooke's law to calculate the spring constant of the elastic string:

F = kx

where F is the force applied, x is the displacement, and k is the spring constant. Rearranging, we get:

k = F/x = 14/0.08 = 175 N/m

Using this spring constant, we can calculate the elongation of the string when a 5 kg mass is hung from it:

m = 5 kg
g = 9.8 m/s^2

F = mg = 5 * 9.8 = 49 N

x = F/k = 49/175 = 0.28 m

Therefore, the total length of the string with the mass hanging from it is:

L = original length + elongation = 40 + 0.28 = 40.28 cm.