Physics Predictions/Thoughts (8 Viewers)

[Hudz777]

View attachment 41326
Can someone please explain this, im so confused! its about the diffraction experiment

they are saying that sinx = tan x = fringeseparation/Length
and for the minima, it is every 1/2 + integer value

 

[Goldattacker40000]

Would we need to be able to explain the Zeeman effect if we had to state limitations of Bohr's model?

 

[Engineer_192931]

Would we need to be able to explain the Zeeman effect if we had to state limitations of Bohr's model?

I think all you need to know is that the spectral lines split into 3 in the presence of a magnetic field and that bohr couldn't account for this.

 

[Engineer_192931]

When you are calculating the energy required to move a satellite higher in orbit do you use the change in GPE or change in total energy way?

 

[SB257426]

Would we need to be able to explain the Zeeman effect if we had to state limitations of Bohr's model?

you dont need to explain it for hsc. it splits into 3 lines and thats all u need ot kno

 

[Goldattacker40000]

When you are calculating the energy required to move a satellite higher in orbit do you use the change in GPE or change in total energy way?

Total energy way I think cause GPE way just tells you how much GPE it gained and doesn't account for the net decrease in kinetic energy of the satellite too.

 

[bvuekwugawesdfv]

Total energy way I think cause GPE way just tells you how much GPE it gained and doesn't account for the net decrease in kinetic energy of the satellite too.

how do u do total energy way again?

 

[Goldattacker40000]

how do u do total energy way again?

I don't think the formula is given in the formula sheet but it's the E=-GMm/2r formula for total energy. Just find the initial value of E using the initial orbital radius given and subtract it from the final value of E using the new orbital radius given.

 

[carrotsss]

When you are calculating the energy required to move a satellite higher in orbit do you use the change in GPE or change in total energy way?

if you're moving it into a new circular orbit then its the change in total energy, if its just moved up (and will fall into an elliptical orbit) then its just the change in GPE. 99% of the time its asking for the first one though

 

[Rattlehead15]

if you're moving it into a new circular orbit then its the change in total energy, if its just moved up (and will fall into an elliptical orbit) then its just the change in GPE. 99% of the time its asking for the first one though

What is change in total energy?

 

[Average Boreduser]

Don’t overcomplicate it, just use the formula on the formula sheet

stfu I hope u get 0

 

[carrotsss]

What is change in total energy?

kinetic energy whilst in orbit is K=-1/2 U (you can derive this if you want but you don't need to), and hence total energy = U + K = U - 1/2 U = 1/2U

 

[Trippzy]

if you're moving it into a new circular orbit then its the change in total energy, if its just moved up (and will fall into an elliptical orbit) then its just the change in GPE. 99% of the time its asking for the first one though

wait I always thought they ask for change in GPE. do u have a question which highlights the first part I haven't ever seen in the use for 1/2U

 

[Goldattacker40000]

View attachment 41318

anyone know what formula to use for this question?

This question is an example of using the total energy change (1/2 U) to find the amount of enegry needed to move a satellite to a higher orbit.

 

[Trippzy]

This question is an example of using the total energy change (1/2 U) to find the amount of enegry needed to move a satellite to a higher orbit.

cant u just use Ufinal - Uinitial? I did that and got the same answer A

 

[Goldattacker40000]

cant u just use Ufinal - Uinitial? I did that and got the same answer A

Using Ufinal-Uinital in this question would give you B instead of A.

 

[Retrodawn]

Usung the

Using Ufinal-Uinital in this question would give you B instead of A.

pretty sure we have to use total energy, so just replace r with 2r and that should do it

 

[Trippzy]

pretty sure we have to use total energy, so just replace r with 2r and that should do it

what would r be in this case?

 

[Goldattacker40000]

what would r be in this case?

The initial value of r would be 6800km and the final value of r would be 42000km, you jusy multiply the denominator of the expression for U by 2 as the total energy of the satellite is given by E=1/2(U). Make sure to convert the values of r to meters

 

[Trippzy]

The initial value of r would be 6800km and the final value of r would be 42000km, you jusy multiply the denominator of the expression for U by 2 as the total energy of the satellite is given by E=1/2(U). Make sure to convert the values of r to meters

so what do I sub in for r in U? 6800km or 42000km