Need help on getting the resonant frequency

AI Thread Summary
To calculate the resonant frequency of a pendulum, use the formula for the period of a simple pendulum, which is T = 2π√(L/g), where L is the length of the pendulum and g is the acceleration due to gravity (approximately 9.81 m/s²). The resonant frequency (f) can then be found using the formula f = 1/T. The discussion highlights the need to determine the period before and after the child kicks, which changes the effective length of the pendulum. Understanding these formulas will help in calculating the resonant frequencies for both scenarios.
xuhhad
Messages
10
Reaction score
0
A 25.0-kg child in Red Deer pumps herself on a swing when she kicks upward on the downswing, thus changing the distance from the pivot point to her centre of gravity from 2.40 m to 2.28 m.

1)The resonant frequency of her swing before the kick is: ___ Hz, and the resonant frequency after the kick is: _____ Hz.

I don't want the answer i just want a hint or a formula i am supposed to use for this, please and thank u. Because my textbook has no examples of it.
 
Physics news on Phys.org
Think of the child as a pendulum.
 
Doc Al said:
Think of the child as a pendulum.

Yes but what do i do from there i am really confused
 
xuhhad said:
Yes but what do i do from there i am really confused
What's the period of a simple pendulum?
 

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Similar threads

Resonance between spring and pendulum: Different frequencies
Replies
4
Views
3K
Frequency problem (static equilibrium)
Replies
2
Views
1K
Problem Set #1: Harmonic Motion and Sound Waves
Replies
5
Views
6K
Simple Physics Questions: Stuck on Equations and Variables? Get Help Here!
Replies
6
Views
6K
Conservation of Energy Post Lab Questions NEED HELP
Replies
2
Views
5K
Physics Final-Multiple Problems-Help
Replies
1
Views
4K
Simple Harmonic Motion General Formula
Replies
2
Views
6K
Help on linear momentum and work/energy problems
Replies
2
Views
5K
How Many Electrons Are Needed to Levitate a Person?
Replies
5
Views
2K
Jestilla Atilla's Journey Through the Warp: A Warhammer 40k Tale
Replies
23
Views
9K

Hot Threads

Recent Insights

Back
Top