Two identical springs, each have k = 20.0 N/m. A 1.00 kg is connected to
them as shown. Calculation the period of motion of the oscillatory system.
Neglect frictional forces.
Answers
Answer:
Explanation:
You find a spring in the laboratory. When you hang 100 grams at the end of the spring
it stretches 10 cm. You pull the 100 gram mass 6 cm from its equilibrium position and
let it go at t = 0. Find an equation for the position of the mass as a function of time t.
Lets first find the period of the oscillations, then we can obtain an equation for
the motion. The period T = 2π
q
m/k. The mass m is 0.1 Kg. To find k, we use the
fact that 100 grams causes the spring to stretch an additional 10 cm. Since F = k∆x,
we have
mg = k∆x
0.1(9.8) = k(0.1)
k = 9.8 N/m
The period of the motion is therefore T = 2π
q
0.1/9.8 ≈ 0.635 sec. At t = 0 the
mass is at its maximum distance from the origin. Thus, x(t) = 0.6 cos(2πt/T). Using
T = 0.635 sec gives
x(t) = 0.6 cos(2πt/0.635)
x(t) ≈ 0.6 cos(9.9t)
The cosine function is the appropriate one, since at t = 0 the mass is at its maximum
distance from equilibrium.