AS Physics P1 MCQs Preparation Thread.

[leosco1995]

View attachment 12097 This is the third time Im posting this, please anyone who is good in moments show me hot to to this!! plssssss

Moment about Q = force * p.d. from pivot
3.0 = f * 50 mm
f = 60 N

(Q just provides an upward force, so there is no couple and hence we don't use the diameter. Don't be confused about a torque always involving a couple, torque just means turning effect and it could apply to a regular moment also.

You already have the answer with this, but anyway for P:

moment = force * distance from pivot
= 60 * 0.75 mm (force was calculated from Q)
= 4.5 Nm

why is the answer C ? that makes no sense at all!!!!

How does it not make sense? Things which are always conserved in a nuclear reaction are mass-energy, charge/proton # and nucleon number. The number of neutrons aren't always the same.

 

[omg]

http://www.xtremepapers.com/papers/...nd AS Level/Physics (9702)/9702_w10_qp_11.pdf
q.s 18 and 9!!!!!!!!!!!!
plsssssssssssssssssssssssssssssssssssssssss

 

[MysteRyGiRl]

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_w05_qp_1.pdf
Q no 16??

 

[leosco1995]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w05_qp_1.pdf
Q no 16??

They try to make this question look hard but it's actually not.

Work done = force * distance moved in direction of force

Force is mg sin ϴ = 10^3 N * sin 30 = 500 N
Distance in direction of force is 5m.

Work = 500 * 5 = 2500 J.

 

[MysteRyGiRl]

They try to make this question look hard but it's actually not.

Work done = force * distance moved in direction of force

Force is mg sin ϴ = 10^3 N * sin 30 = 500 N
Distance in direction of force is 5m.

Work = 500 * 5 = 2500 J.

u didnt use g value?

 

[shan5674]

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_s08_qp_1.pdf

No. 14? please?

 

[leosco1995]

u didnt use g value?

No because mg was already given (10^3 N). If they said 10^3 kg, then you would multiply by g.

 

[MysteRyGiRl]

No because mg was already given (10^3 N). If they said 10^3 kg, then you would multiply by g.

ohh didnt see dat,thnx and can u plz explain hw we got sin here? :/ i got cos first

 

[USMAN Sheikh]

No because mg was already given (10^3 N). If they said 10^3 kg, then you would multiply by g.

can u solve my questions too pls MR genius

 

[USMAN Sheikh]

I see, thanks.

can u pls solve them plsmates i am posting dis another time plssssssssssssssssssss help me on these can anyone pls help me out on these question plssss 6 24 30 39 pls

 

[USMAN Sheikh]

No because mg was already given (10^3 N). If they said 10^3 kg, then you would multiply by g.

and these too pls u r help will be appreciated q 5 13 15 18

 

[leosco1995]

ohh didnt see dat,thnx and can u plz explain hw we got sin here? :/ i got cos first

You use sin when you want to find the component parallel to the slope (i.e. opposite to the direction of friction). If you want to find the component down the slope, then you use cos. See the attached diagram.

grey = mg sin ϴ
green = friction (opposite to mg sin ϴ)

black = mg cos ϴ
red = normal contact force (opposite to mg cos ϴ)

mg sin ϴ is parallel to the slope and opposite to the frictional force, while mg cos ϴ is down the slope and opposite the normal contact force. You don't have to worry about the frictional/contact forces, they will be given in the question.

Over here, the force was parallel to the slope so we used sin.

I hope this helped.

 

[MysteRyGiRl]

You use sin when you want to find the component parallel to the slope (i.e. opposite to the direction of friction). If you want to find the component down the slope, then you use cos. See the attached diagram.

grey = mg sin ϴ
green = friction (opposite to mg sin ϴ)

black = mg cos ϴ
red = normal contact force (opposite to mg cos ϴ)

mg sin ϴ is parallel to the slope and opposite to the frictional force, while mg cos ϴ is down the slope and opposite the normal contact force. You don't have to worry about the frictional/contact forces, they will be given in the question.

Over here, the force was parallel to the slope so we used sin.

I hope this helped.

thank u loadzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz

 

[kinglynx]

Moment about Q = force * p.d. from pivot




How does it not make sense? Things which are always conserved in a nuclear reaction are mass-energy, charge/proton # and nucleon number. The number of neutrons aren't always the same.

Thats not true, in Beta decay, often one side will have one more proton than the other due to the nature of the decay (a proton and electron together) so charge/proton cant be, thus if the proton number isnt conserved neither can be the nucleon number. Also neutron number then isnt conserved either, it makes no sense!!!

 

[MysteRyGiRl]

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_w05_qp_1.pdf
Q no 18 plzz

 

[ibadsiddiqi]

Thats not true, in Beta decay, often one side will have one more proton than the other due to the nature of the decay (a proton and electron together) so charge/proton cant be, thus if the proton number isnt conserved neither can be the nucleon number. Also neutron number then isnt conserved either, it makes no sense!!!

in beta decay, one neutron splits to form a proton and an electron, so the nucleon number is conserved

 

[ibadsiddiqi]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w05_qp_1.pdf
Q no 18 plzz

LOL i just used the formula pressure=density x g x h for both of them in each option and the one in which the pressure was the same for both liquids that was the height. Thats option C

 

[MysteRyGiRl]

LOL i just used the formula pressure=density x g x h for both of them in each option and the one in which the pressure was the same for both liquids that was the height. Thats option C

where did u get h or presure from?

 

[ibadsiddiqi]

you

where did u get h or presure from?

have the densities, you have g, the heights are given in each option..use the pressure formula to find the pressure in each option.
eg the correct option is C
in C depth in liquid X is 15m
depth in liquid Y is 10m
use the formula pressure= density x h x g
so for liquid X, P=800x 15 x 9.81=117,200
for liquid Y= 1200x 10 x 9.81=117,200
pressures are equal for the depth given in option C. so thats the answer

 

[MysteRyGiRl]

you
have the densities, you have g, the heights are given in each option..use the pressure formula to find the pressure in each option.
eg the correct option is C
in C depth in liquid X is 15m
depth in liquid Y is 10m
use the formula pressure= density x h x g
so for liquid X, P=800x 15 x 9.81=117,200
for liquid Y= 1200x 10 x 9.81=117,200
pressures are equal for the depth given in option C. so thats the answer

lolzz ok thnx