Physics: Post your doubts here!

[Browny]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s12_qp_21.pdf

Can anyone explain why 0.4s is wrong for 3)b)ii) ?

 

[Suchal Riaz]

the reason is a little but difficult to grasp but i will try to explain.

as you can see the change is length is maximum at zero second, when the mass is pulled not when it is compressed because:
at 0.0 s and 8.0 s
e=initial extension due to mass + d
at 0.4 s
e=d-initial extension due to mass
so when the extension is highest the spring has highest elasic potential energy.

 

[Suchal Riaz]

Question 5 bii) iii) iv)

of which paper rohan

 

[Thought blocker]

the reason is a little but difficult to grasp but i will try to explain.
View attachment 41685
as you can see the change is length is maximum at zero second, when the mass is pulled not when it is compressed because:
at 0.0 s and 8.0 s
e=initial extension due to mass + d
at 0.4 s
e=d-initial extension due to mass
so when the extension is highest the spring has highest elasic potential energy.

Mere bhi doubt solve kardo

 

[Thought blocker]

of which paper rohan

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s12_qp_23.pdf
Its easy but I forgot some few concepts :'(

 

[Suchal Riaz]

Mere bhi doubt solve kardo

konse doubt. aap ka nokar hun hukam karo

 

[Thought blocker]

konse doubt. aap ka nokar hun hukam karo

LOL ARE YOU FREE ?

 

[DeViL gURl B)]

Aoa,
Guys if anyone of u have COMPLETE PHYSICS DEFINATIONS FOR AS Level ... Please share!
As well as the best and detailed explanation for projectile motion ... Would be well appreciated
URGENT HELP PLEASE!
Thank you

 

[Suchal Riaz]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s12_qp_23.pdf
Its easy but I forgot some few concepts :'(

 

[Suchal Riaz]

LOL ARE YOU FREE ?

no i am not free but always free to help

 

[Thought blocker]

no i am not free but always free to help

can u inbox me

 

[Thought blocker]

View attachment 41690

Y u used in part ii) IV and in part iii) I^2R ?

 

[Suchal Riaz]

can u inbox me

what do u want?

 

[Thought blocker]

what do u want?

Wait I'll inbox you.

 

[Suchal Riaz]

Y u used in part ii) IV and in part iii) I^2R ?

V=IR
in P = IV use (v=ir)
P=I(IR)=I²R

 

[Thought blocker]

V=IR
in P = IV use (v=ir)
P=I(IR)=I²R

Still din't get you, y we dont use P=V^2/R in part ii) or P = IR in part iii) ?

 

[Suchal Riaz]

Still din't get you, y we dont use P=V^2/R in part ii) or P = IR in part iii) ?

we can use any of them as long as we use correct value or R, V and I
i used the one with I and V because the generator's emf and I already given.
and in other part i used the one with I because if i used V when i would have to find the p.d across resistors. if we used P=V²/R = 8²/4=16. same answer.

 

[Thought blocker]

we can use any of them as long as we use correct value or R, V and I
i used the one with I and V because the generator's emf and I already given.
and in other part i used the one with I because if i used V when i would have to find the p.d across resistors. if we used P=V²/R = 8²/4=16. same answer.

ty

 

[Zepudee]

We use P=VI to determine the efficiency? and how do we use it? Can give some examples? Thanks a lot!!

 

[Thought blocker]

We use P=VI to determine the efficiency? and how do we use it? Can give some examples? Thanks a lot!!

Use efficiency formula, (Input power / output power) * 100