Physics: Post your doubts here!

[Tom Sewage]

This plz
View attachment 64182

is the answer D

 

[khadijaimran]

24. i know the obsv. freq will inc what about the other part?
21. how will i know this?

 

[Hisham Khan]

24. i know the obsv. freq will inc what about the other part?
21. how will i know this?
View attachment 64190 View attachment 64191

 

[Hisham Khan]

24. i know the obsv. freq will inc what about the other part?
21. how will i know this?
View attachment 64190 View attachment 64191

The dopplers effect also depend on speed of object.Observed frequency will decrease according to formula if speed of object decrease

 

[Hisham Khan]

Even tho I am retaking physics,It may help you anyway.
Kanekii can you tell me some useful physics books for revision and something really useful

 

[A*****]

is the answer D

Its B

 

[Ayesha_m01]

A ig

sorry what?

 

[hellodjfos;s'ff]

View attachment 64193
its B... how?
and why not C

There's no legit reasoning for this. The most you can do is use a few numbers to test out which equation is correct.

 

[hellodjfos;s'ff]

You guys asked lots of questions over the last couple of pages and I can't do them all... just tell me which tough ones you want explained as soon as possible.

 

[Ayesha_m01]

There's no legit reasoning for this. The most you can do is use a few numbers to test out which equation is correct.

hmmm... may God bless you...

 

[dwightedknight]

I pray I don't get a D this time too. Best of luck to everyone.

 

[hellodjfos;s'ff]

Yeah good luck to all

 

[Ayesha_m01]

ummm its D???

 

[Ayesha_m01]

ANS is C.... can someone show me the stepss

 

[hellodjfos;s'ff]

View attachment 64194 ummm its D???

For equilibrium, clockwise moments=anticlockwise moments
20(0.4)=10(0.6)+100(0.1)
8=16
You can clearly see that there is a lack of moment for clockwise, so the 20N weight must be placed towards the right side of the pivot. Also, there's a lack of 8Nm moment, so the 20N weight must have a moment of 8Nm.
8=20*D
D=8/20=0.4 m
This means that the extra 20N must be placed 0.4 m from the pivot to the right. This position is D

 

[hellodjfos;s'ff]

View attachment 64195
ANS is C.... can someone show me the stepss

Use the formula we use in maths mechanics paper. Wd by object-wd by air resistance=KE gain-GPE loss

 

[Hisham Khan]

gl lul

 

[Ebrahim12]

Answer is C
Why is D right but not C?

 

[Hisham Khan]

Paper was kinda tough and ok at the same time.
Wasthe displacement time graph like this?

 

[Tom Sewage]

View attachment 64195
ANS is C.... can someone show me the stepss

work done= GPE-KE
F*h= mgh - 0.5mv*2
F= mgh divide by h - 0.5mv*2 divide by h
F= mg - 0.5mv*2 divide by h
F= m ( g - 0.5v*2divide by h)