OK, so my last comments in this thread: a rod can start unloading before the end of acceleration, it is a matter of a few 1/100 seconds and nobody cares but me. Merlin - F=ma In this case the F can be measured by the bend in the rod (remember all the times I've said that the rod, although not linea...

The spring in a sense takes kinetic energy out of the falling brick and transfer it to the sliding brick (the falling brick does more work on the other brick when the spring is introduced). The mechanism is exactly the same as for the brick-spring-car model, only the boundary condition is changed (...

So, in summary: Grunde says that in his model the higher energy output of the spring connection comes from a higher energy input form the caster. In my experiment (and I proposed it just for this reason) the energy input is exactly the same in both cases. However Merlin's model gives and advantage ...

As I said I am not after actual numbers but after visual clues which result evident for everyone without complex graphs reading skills, just using the naked eye. So, since you said that fundamentally agree with Trev's analysis I have enough with these parts of his (yours)predictions (underlining is...

VGB wrote:

grunde wrote:No, this is only due to the spring. I've made no assumption on MOI or weight on rod/broomstick.

Are you talking only about the model?

If its instant coffee, white with one sugar please

regards

Vince

No, about bouth the model and real casting.

Instant coffee only when very desperate...

Both strokes are equal in acceleration but they are different in force (thus work)? Is that due to the higher moment of inertia of the broomstick? No, this is only due to the spring. I've made no assumption on MOI or weight on rod/broomstick. Beer or coffee; that is completely up to you :D Cheers, ...

Hi James, in the BSC model we make no assumption about the energy and mass of the car. In fact the way it moves is just imposed as a boundary condition, and we are then just interested how this imposed boundary condition affects the spring and the attached brick. So I don't think this is correct: R...