Pushing on the pump of a soap dispenser compresses a small spring. When the spring is compressed 0.54 cm, its potential energy is 0.0025 J.
(a) What is the force constant of the spring? (answer is in kN/M)
(b) What compression is required for the spring potential energy to equal 0.0078 J? (answer is in cm),
We know, U of spring = (kx^2)/2
k = spring constant
x = deflection from mean position
a) Here, x = 0.54 cm = 0.0054 m
U= 0.0025 J
k = 2U/x^2
k = 0.0050/ (0.0054^2)
k = 0.171 kN/m
b) x = (2U/k) ^ 1/2
x = (0.0156/171) ^ 1/2
x = 0.0095 m
x = 0.95 cm
