EDEXCEL Unit 5 Physics Discussions - IAL only

Original post by Daniel Atieh

What was the answer for the mcq question asking about SHM?
I chose none of the energies.

I chose all of them. Because in every textbook we're always taught the total energy is constant constant constant. and that was the only choice which allowed it. and although PE and KE varies....i suppose the "total" or overal KE and PE is in a sense constant. omg i dont know.

Reply 22

Original post by Daniel Atieh

Yeah, but the first one was 1.42 J i think ?
The one just before the impact.

oh yes i got 1.42 J somewhere...don't remember the question tho!

Reply 23

Original post by saifulahmed

26'C

were we supposed to fill it in the table or just write it? and I gave my answer in Kelvin.

Reply 24

Original post by Munchee

oh yes i got 1.42 J somewhere...don't remember the question tho!

Heyy

How was the exam for you? What boundary for a* you think it will be?
What did you slect for the shm mcq?
is lead suitable for that question asking about material?

Reply 25

Original post by Daniel Atieh

I really forgot what i did here. I think i used the equations separately, but i believe i got it correct.

Why alpha particle gained most of the energy?

becuase alpha particle is much lighter (less massive) so easier to accelerate becuase less inertia. but i dont think inertia is in our syllabus, so is it okay to just say smaller mass so gains more KE...

Reply 26

I think a* would be in the range of 70 to 75. It wasn't a bad paper, at least compared the **** that was c4 and Chem unit 5.
The Shm question was confusing,,,i felt like they should have had total energy as an option, but it wasn't so I went with none of them. What was your answer for the first mcq, about the K.E of nitrogen and oxygen?

Yeah I think lead would work. It would stop gamma rays...but I put concrete. Isn't that the standard material they use?

Reply 27

Original post by janine803

becuase alpha particle is much lighter (less massive) so easier to accelerate becuase less inertia. but i dont think inertia is in our syllabus, so is it okay to just say smaller mass so gains more KE...

Yeah i also wrote that.

Reply 28

Unofficial ms anyone? :biggrin:

Reply 29

Original post by Munchee

I think a* would be in the range of 70 to 75. It wasn't a bad paper, at least compared the **** that was c4 and Chem unit 5.
The Shm question was confusing,,,i felt like they should have had total energy as an option, but it wasn't so I went with none of them. What was your answer for the first mcq, about the K.E of nitrogen and oxygen?

Yeah I think lead would work. It would stop gamma rays...but I put concrete. Isn't that the standard material they use?

KE od them is the same.

I put concrete not lead.

Reply 30

AliNSiddiqui

2

Original post by janine803

becuase alpha particle is much lighter (less massive) so easier to accelerate becuase less inertia. but i dont think inertia is in our syllabus, so is it okay to just say smaller mass so gains more KE...

I wrote smaller mass so greater velocity required to maintain momentum. KE=0.5mv2 so kinetic energy also increases. Not sure about it though

Reply 31

AliNSiddiqui

2

Original post by Munchee

I think a* would be in the range of 70 to 75. It wasn't a bad paper, at least compared the **** that was c4 and Chem unit 5.
The Shm question was confusing,,,i felt like they should have had total energy as an option, but it wasn't so I went with none of them. What was your answer for the first mcq, about the K.E of nitrogen and oxygen?

Yeah I think lead would work. It would stop gamma rays...but I put concrete. Isn't that the standard material they use?

Conservation of energy isn't a requirement for SHM. in damping systems, dampers dissipate energy but it is still SHM. Correct answer was none of the above.

Reply 32

Original post by talalf

1. Open universe
2. Doppler shift of side x moving away from us
3. Temperature increases as molecules get kinetic energy from ball, molecules have more momentum, greater impulse when colliding with walls of container, increases pressure.
4. Got the same answer
5. Same, got 299k
8. Yep got 21.1 hours

i also wrote that but then i realized they wanted you to make use of the info given in the question about the size of the rocks. so i said one with the longer wavelength (X) has smaller rocks which is receding faster than the larger rocks becuase they are in the same ring, so thats why X has a larger red shift.

did anyone else write this for the Saturn's Ring question

Reply 33

Original post by Munchee

I think a* would be in the range of 70 to 75. It wasn't a bad paper, at least compared the **** that was c4 and Chem unit 5.
The Shm question was confusing,,,i felt like they should have had total energy as an option, but it wasn't so I went with none of them. What was your answer for the first mcq, about the K.E of nitrogen and oxygen?

Yeah I think lead would work. It would stop gamma rays...but I put concrete. Isn't that the standard material they use?

Omg thats too high :/ It must be lower than 74 or am dead :/
I think it was the same or something?

Reply 34

Original post by janine803

KE od them is the same.

I put concrete not lead.

oops...i put oxygen has a higher K.E...there was a similar question once where they said oxygen has a higher mass than Nitrogen, therefore Oxygen has a greater K.E

Reply 35

jan 2014 A* was 67...do you think this one will be higher or the same? I hope it's not 70+ for an A* though. that is very rare...and unit 4 didn't go so well so we need a high score for unit 5 to boost it up to an A* overall ><

Reply 36

Original post by AliNSiddiqui

Conservation of energy isn't a requirement for SHM. in damping systems, dampers dissipate energy but it is still SHM. Correct answer was none of the above.

Wishing I had your brains...

Reply 37

Original post by Munchee

Wishing I had your brains...

dammit. yes, you're right. arghhhh.

can anyone remember what the MCQ was asking about what affects the g on a person or something? and what was the answer for that?

Reply 38

Mouse233

3

I think this one have a similar difficulty as the 14 Jan one, so the boudary for a* might be around 67...?

Reply 39