Recent content by Maggie

Yes I got the same answer, but this equation is more abstract to me, I like that momentum method better:)

thank you! so tricky this question

okkkkay thanks. but just to confirm my calculation. the initial Ek will be 0.5*9.6*(14.6)^2=1023.168J, and the final Ek for m1 is 0.5*9.4*14.962^2=1052.149J, since energy is scalar, the direction doesn't matter, the final Ek for m2 is 0.576J, the total final Ek is 1052.725J. And the difference...

okay now I understand, but once I got the final velocity of m1, what should I do next? using EK equation?

do you mean that the m1+m2=9.6kg? So actually m1 is only 9.4kg? oh I misunderstood all the time... so the initial momentum is 9.6*14.6=+140.16kgm/s, then the final would be (140.16+0.48)/9.4=14.962m/s?

ohhh I just knew that energy is scalar but forgot about momentum... okay. So the final momentum of m1 would be (143.08-(-)0.48)/9.6=+14.954m/s, right?

Now I got it clearer, so the initial momentum is (9.6+0.2)*(14.6)=143.08, and the final momentum of m2 is 0.48, so the difference is 142.6, then 142.6/9.6=14.854m/s, this is the final v of m1. Then how can I deal with this final v?

Do you mean that the momentum of the two masses before should be calculated by v(m1+m2)? which is 9.8*14.6?? But I don't understand why the initial momentum should include both masses...

is the momentum calculated by mv? then: momentum of the mass before= explosion momentum+momentum of the mass after? and initial momentum is 140.16 and final is 0.48, the difference is 139.68

I only know that the momentum should be conserved since no external force applied, so the difference between pi and pf should be the momentum of the explosion? I'm confused now...

but how? I calculated the initial p is 140.16 and final p is 0.48, the difference is 139.68, how can I transfer this answer into energy?

I remembered energu conservation, momentum conservation, and probably charge (not relevant)... should I use momentum in this question?

Hello, I think the only energy involved is kinetic energy. So I subtract to get the difference between two stages to find the energy cost by explosion. (0.5*9.6*14.6^2)-(0.5*0.2*2.4^2)=1022.59J However the system said that this answer is wrong, So I wondered where did I make a mistake?

Thank you so much now I got that!

I think the force, is that centripetal force of Block B only?