- #1
moenste
- 711
- 12
Homework Statement
A particle moves with simple harmonic motion in a straight line with amplitude 0.05 m and period 12 s. Find: (a) the maximum speed, (b) the maximum acceleration, of the particle.
Write down the values of the constants P and Q in the equation x / m = P sin [Q (t / s)] which describes its motion.
Answers: (a) 0.026 m s-1, (b) 0.014 m s-2, P = 0.05, Q = π / 6
2. The attempt at a solution
(a) I used the v = (2 π r) / T formula for this part: v = (2 * π * 0.05) / 12 = 0.026 m s-1.
(b) For acceleration I used this formula: a = v2 / r → a = 0.0262 / 0.05 = 0.0137 m s-2.
In terms of P and Q I am somewhat lost. Let's take a look at the formula provided:
- I think x is the extension = 0.05 m
- m is the mass, which is unknown and I don't know how to find it (I can only think of KE, but in that case I'll have two unknowns -- KE and m)
- Both P and Q are unknown, I think we need to plug everything in and then derive P (P = (x / m) / sin [Q (t / s)]) and then plug P into the original equation, but not sure
- t should be time = 12 s
- s should be the distance moved s = v t = 0.026 * 0.05 = 1.3 * 10-3 m
In sum, if my logic is correct, I don't see a way how to find m. And I my logic is wrong, how should I approach the given formula?