Physics: Post your doubts here!

[Yousif Mukkhtar]

for Q4 a ii)
Ek = p^2/2m
1/2mv^2 = (mv)^2/2m (since, p=mv)
1/2mv^2= mv^2/2 (m and m cancels out)
1/2mv^2 = 1/2mv^2. (Hence, Proven)

for Q4 b i)
find change in momentum first,
delta p = m*delta v
p= 0.035*(4.5+3.5)
p=0.28.
F=change in momentum/change in time
F=0.28/0.14
F=2.0N.

Thanks a lot.

Can someone explain this question?

 

[emkay]

Thanks a lot.

Can someone explain this question?

for minimum force to be applied the angle is always 90 degree.
and for second part,
Torque = Force*distance
Force=Torque/distance
F=130/0.45
F=290N

 

[Yousif Mukkhtar]

for minimum force to be applied the angle is always 90 degree.
and for second part,
Torque = Force*distance
Force=Torque/distance
F=130/0.45
F=290N

Thanks again brother.

 

[Trisha Graal Emile]

A 120 kg crate is dragged along the horizontal ground by a 200 N force acting at an angle of 30° to the horizontal. The crate moves along the surface with a constant velocity of 0.5 m s–1. The 200 N force is applied for a time of 16 s.

a Calculate the work done on the crate by:
i the 200 N force
ii the weight of the crate
iii the normal contact force R.
b Calculate the rate of work done against the frictional force FR.

 

[A*(a*)]

A 120 kg crate is dragged along the horizontal ground by a 200 N force acting at an angle of 30° to tswhe horizontal. The crate moves along the surface with a constant velocity of 0.5 m s–1. The 200 N force is applied for a time of 16 s.

a Calculate the work done on the crate by:
i the 200 N force
ii the weight of the crate
iii the normal contact force R.
b Calculate the rate of work done against the frictional force FR.

Are these answers correct and is it from past papers ?
ai 200cos(30) * 8 J
aii 120*9.81 N
aiii 120*9.81 - 200sin(30) N
b 1600 cos(30) / 16 W

 

[Adeel12346]

Can anyone plz help me in Question 12
http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s12_qp_11.pdf

Thankx in Advance

 

[ISFSAT]

http://www.freeexampapers.com/past_papers.php?l=Past_Papers/A+Level/Physics/CIE/1999+Jun/
Can anyone solve the Q.3 of Paper2...Please...

 

[Adeel12346]

http://www.freeexampapers.com/past_papers.php?l=Past_Papers/A Level/Physics/CIE/1999 Jun/
Can anyone solve the Q.3 of Paper2...Please...

Can u plz provide me the mark scheme to confirm my answers ... I will try to help u as soon as possible

 

[Soldier313]

Aoa wr wb , could someone please help me with qn 4 a) i just don't get the logic behind saying that the energy is decreasing so it'a an attractive force
http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s12_qp_42.pdf

thanx a lot
need urgent help

 

[ISFSAT]

Can u plz provide me the mark scheme to confirm my answers ... I will try to help u as soon as possible

that was the main problem...i tried to find the mark scheme...but i did not find...

 

[Adeel12346]

hmmm

 

[umair999]

Hi everyone, AsSalamoAlaikum Wr Wb...

To get things organized in a better way, I am making this thread. As othewise, some queries remain unanswered!

So post your PHYSICS doubts in this thread. InshaAllah other people here will help me and you all.

NOTE: If any doubts in the pastpapers, please post the link! You can find links here!

Any Physics related notes and links will be added here in this post. Feel free to provide the links to your notes around the forum, or any other websites!
Thanks!
Jazak Allah Khair!

Physics Notes:

Some links & Notes - by destined007

Physics Practical Tips - by arlery

Notes for A2 Direct Sensing (Applications) - shared by sweetiepie

Physics Summarised Notes (Click to download)

AS and A-Level Physics Definitions

A2: Physics Revision notes - by smzimran

Paper:5 Finding uncerainty in log - by XPFMember

Physics Paper 5 tips - by arlery

Physics Compiled Pastpapers: <Credits to CaptainDanger for sharing this..>

Here are the compiled A level topical Physics questions in PDF form...

Paper 1 : http://www.mediafire.com/?tocg6ha6ihkwd

Paper 2 & Paper 4 : http://www.mediafire.com/?g65j51stacmy33c

(Source : http://www.alevelforum.com/viewtopic.php?f=15&t=14)

where are the answers of mcq's(paper 1)

 

[Adeel12346]

I think u will have to see mark scheme from papers section... U can see which year u are doing at the moment and then u can see it or download it from papers section ... Hope it helps u

 

[Yousif Mukkhtar]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w10_qp_11.pdf
Can someone explain q5?

 

[emkay]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w10_qp_11.pdf
Can someone explain q5?

As it says, 3000 revolutions/min (apply unitary method)
3000 = 60sec
1 = x
x = 60/3000
x= 0.02s(one wave) in the 10cm wide display of c.r.o
looking at the options, the second one
showing 10ms means 0.01
and 0.01*2 = 0.02 means one wave and when we multiply 0.02*5 (as there could be 5 waves made in the 10cm wide display of c.r.o) or (10*10^-2/0.02 = 5) = it gives 0.1 i.e the option B.
(as 10ms-1 = 0.01)

 

[Yousif Mukkhtar]

As it says, 3000 revolutions/min (apply unitary method)
3000 = 60sec
1 = x
x = 60/3000
x= 0.02s(one wave) in the 10cm wide display of c.r.o
looking at the options, the second one
showing 10ms means 0.01
and 0.01*2 = 0.02 means one wave and when we multiply 0.02*5 (as there could be 5 waves made in the 10cm wide display of c.r.o) or (10*10^-2/0.02 = 5) = it gives 0.1 i.e the option B.
(as 10ms-1 = 0.01)

Thanks again for saving another lost soul

 

[Yousif Mukkhtar]

Guys one last question:
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s12_qp_12.pdf
q13 and 15

 

[D0cEngi]

Plz help me with Q.5 part (b) of this paper: http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s08_qp_4.pdf
here is the ms : http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s08_ms_4.pdf

 

[emkay]

Guys one last question:
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s12_qp_12.pdf
q13 and 15

for 13,
Forward force - Frictional Force = Mass*Acceleration
Forward Force = 2.0*9.81
Frictional Force = 6N
Mass (net)= 8.0 + 2.0
Acceleration = F-f/mass
a=19.62-6/10
a=1.36 or 1.4 i.e A is the answer.
---
for 15,
since tourqe is equal to force*distance,
the distance moved by the spindle will be the torque,
i.e L/4 means, WL/4 and will always be clockwise in this condition
ps. this was a stupid question just remember the fact that the distance moved by
the spindle will be multiplied by the weight of the cube W.

 

[A*(a*)]

i hav dem for A level chptrs..u want AS or A?

AS ..I want them badly...please if you could give it to me ?