Solving the Spring-Weight Paradox: 0.039m

  • Thread starter Thread starter Speedking96
  • Start date Start date
  • Tags Tags
    Paradox
AI Thread Summary
The discussion focuses on solving the spring-weight paradox by analyzing the forces acting on a spring when a weight is applied. The initial calculation shows that at maximum stretch, the spring force equals the weight, leading to a stretch of 0.01962 m. However, the solution key indicates the maximum stretch should be 0.039 m, prompting a reevaluation of the approach. The conversation suggests using the conservation of energy principle to address the discrepancy, particularly considering the effects of sudden changes in weight. This indicates a need to account for dynamic conditions rather than static equilibrium in the analysis.
Speedking96
Messages
104
Reaction score
0

Homework Statement


upload_2014-11-23_7-54-12.png


Homework Equations



Fs = -kx

w = mg

The Attempt at a Solution



I said that when the spring is stretched out at its max, the weight pulling down will equal the force of the spring pulling up.

Fs=w
-kx = mg
-(1500)(x) = (3)(-9.81)

x = 0.01962 m

The solution key tells me the max stretch is double this amount, 0.039 m. What is wrong with my approach?
 
Physics news on Phys.org
Mark the word suddenly. If the basket were at maximum distance and forces would be in equilibrium, the velocity wouldn't change anymore, so the thing would hang still.
Do you think that is what would happen if you suddenly put a brick in the basket ?
 
Last edited:
Ah. I see. So then I need to solve the problem using the conservation of energy.
 

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

What is the Velocity of a Rotating Weight?
Replies
5
Views
2K
Solving the Spring Paradox: Uncovering the Error
Replies
4
Views
2K
Calculating Initial Height of a Falling Safe on a Spring
Replies
5
Views
2K
Vibration Problem: Determine Period
Replies
4
Views
2K
How to solve a differential equation for a mass-spring oscillator?
Replies
2
Views
2K
What is the total length of the bungee cord in this bungee jumping problem?
Replies
26
Views
3K
A block of mass m is dropped onto the top of a vertical spring....
Replies
8
Views
5K
Shm , calculation of amplitude of spring mass system
Replies
3
Views
2K
Summing the forces for an object hanging from a spring.
Replies
13
Views
5K
How Do You Calculate the Period of Oscillation for a Mass on a Spring?
Replies
16
Views
3K

Hot Threads

Recent Insights

Back
Top