Elastic Springs and Strings

Question 1

Tension formula

Answer 1

T = λx/l

Question 2

λ

Answer 2

Modulus of elasticity, units N

Question 3

Two springs connected

Answer 3

Set the tension equal and the extension in one to x and the other (changeInLength - x) and find the tension in the combined spring with the tension of each

Question 4

Attaching a particle to a string

Answer 4

It will angle down, dividing into two strings effectively, use trig for the new length of each

Question 5

Two vertical springs with a mass below

Answer 5

The tension in each is equal to the weight so you can find each extension

Question 6

Tension on a compressed string

Answer 6

Acts towards the original length of the string

Question 7

Elastic potential formula

Answer 7

E = λx^2/2l

Question 8

Conservation of energy

Answer 8

(Total elastic, kinetic and gravitational energies at start) + (W.D by forward force - W.D by resistive force) = (Total elastic, kinetic and gravitational energies at end)

Question 9

Energy problems with 2 strings

Answer 9

Double the elastic potential energy of each string