Body on a spring: expression for the period T

Click For Summary
SUMMARY

The period T of vertical oscillations for a mass m suspended from a helical spring with force constant k is expressed as T = 2 π √(m / k). When two identical springs are joined in series, the effective spring constant becomes k/2, resulting in a new period of T = 2 π √(m / (k / 2)). In the case where the springs are arranged in parallel, the effective spring constant doubles to 2k, leading to a period of T = 2 π √(m / (2k)). The calculations confirm the relationship between spring configuration and oscillation period.

PREREQUISITES
  • Understanding of Hooke's Law and spring constants
  • Familiarity with the concept of oscillatory motion
  • Basic knowledge of algebra and square roots
  • Ability to manipulate equations involving physical constants
NEXT STEPS
  • Study the derivation of the formula for the period of oscillation in simple harmonic motion
  • Explore the effects of damping on oscillatory systems
  • Learn about the differences between series and parallel spring configurations
  • Investigate real-world applications of spring oscillations in engineering
USEFUL FOR

Students studying physics, particularly those focusing on mechanics and oscillatory motion, as well as educators seeking to clarify concepts related to spring dynamics.

moenste
Messages
711
Reaction score
12

Homework Statement


(a) A body of mass m is suspended from a vertical, light, helical spring of force constant k, as in Fig. 1. Write down an expression for the period T of vertical oscillations of m.

(b) Two such identical springs are now joined as in Fig. 2 and support the same mass m. In terms of T, what is the period of vertical oscillations in this case?

(c) The identical springs are now placed side by side as in Fig. 3, and m is supported symmetrically from them by means of a weightless bar. In terms of T, what is the period of vertical oscillations in this case?

2bda1af4ce78.jpg


2. The attempt at a solution
(a) The first figure looks like a basic example of a body on a spring and it's period should be: T = 2 π √(m / k).

(b) Since there are two identical springs, I would say that their force constant k should be less, because the spring is longer now: T = 2 π √(m / (k / 2)).

(c) Since the two springs are in parallel, the force constant k should be twice as much: T = 2 π √(m / (2k)).

I am not sure for the (b) and (c) parts. If we take the (a) formula as the basis, the only thing (as I see it) that changes is k due to the different spring positions. So, for (b) it should be (k / 2) and for (c) 2k. I am going in the right direction?
 
Physics news on Phys.org
moenste said:
If we take the (a) formula as the basis, the only thing (as I see it) that changes is k due to the different spring positions. So, for (b) it should be (k / 2) and for (c) 2k. I am going in the right direction?
Exactly right! :thumbup:
 
  • Like
Likes   Reactions: moenste

Similar threads

  • · Replies 5 ·
Replies
5
Views
1K
Replies
24
Views
4K
  • · Replies 14 ·
Replies
14
Views
4K
Replies
7
Views
1K
Replies
16
Views
2K
Replies
3
Views
1K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
9
Views
4K
Replies
9
Views
2K
  • · Replies 10 ·
Replies
10
Views
1K