Help finding potential energy of spring.

AI Thread Summary
The discussion revolves around a scenario involving two blocks compressing a spring and then being released on a frictionless surface. Block A has a mass of 1.00 kg and Block B has a mass of 3.00 kg, with Block B reaching a speed of 1.10 m/s after release. The final speed of Block A is calculated to be 3.30 m/s. Participants are trying to determine the potential energy stored in the compressed spring, with an initial kinetic energy calculation of 9.075 being questioned for accuracy. The conversation emphasizes the need for correct calculations to find the potential energy of the spring.
jgibbon2
Messages
7
Reaction score
1
Block A has mass 1.00 kg, and block B has mass 3.00 kg. The blocks are forced together, compressing a spring between them; then the system is released from rest on a level, frictionless surface. The spring, which has negligible mass, is not fastened to either block and drops to the surface after it has expanded. Block B acquires a speed of 1.10 m/s.

a) What is the final speed of block A? Found this answer to be 3.30 m/s

b) How much potential energy was stored in the compressed spring?
- how do you find this answer?? KEa+KEb=9.075 ... not right
 
Physics news on Phys.org
check again your math in the KE calculation.
 
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

Distribution of Energy when work is done on a system of 2 masses connected by a spring
Replies
17
Views
2K
Why can we move the spring with constant speed when we apply a force?
Replies
29
Views
2K
Find elastic energy in the compressed spring.
Replies
12
Views
3K
Hooke's Law using Potential Energy
Replies
21
Views
1K
Problem with when to use Force and Energy. What compresses spring/
Replies
3
Views
1K
Question about springs and rotational/translational energy
Replies
4
Views
1K
A rocket on a spring, related to potential/kinetic energy
Replies
3
Views
2K
Help finding the change in potential energy in this problem
Replies
9
Views
768
Find the potential, kinetic, and mechanical energy
Replies
22
Views
4K
Why is my method for finding the spring constant incorrect?
Replies
17
Views
3K

Hot Threads

Recent Insights

Back
Top