Biology; Chemistry; Physics: Post your doubts here!

[Dark Destination]

Same for efficiency,though piston one is wrong i guess ,i wrote it travels less distance to reduce friction between cylinder and piston and therefore ensure max energy transfer to the arm.

What about expansion question?
I didn't choose any of those options with SLIGHTLY in it :/
Solids expand way less than liquids. Not slightly less. Am i right?

 

[princess Anu]

Is it important to write only 15 points in notes for summary writing? or can we write as much as we can ?

 

[Lilly2318]

http://papers.xtremepapers.com/CIE/...el/English Language (1123)/1123_w13_in_22.pdf
see this what the heck is in passage 2
chawlian

 

[Lilly2318]

Is it important to write only 15 points in notes for summary writing? or can we write as much as we can ?

only first 15 will be checked, no use writing extra

 

[Dark Destination]

it can never be kinetic as decrease in k.e = gain in gpe . So answer is acceleration

If you're talking about the question where something was to be constant but not zero.. it wasn't acceleration.. As acceleration was zero..

 

[Dark Destination]

only first 15 will be checked, no use writing extra

How to get 15/15 in summary points? I always get 13 in school exams.

 

[DaniyalK]

According to Pure Physics, Work = Force * Displacement. Energy in the system is constant so work will remain the same. Since the force on the second piston is larger, the displacement will be smaller to keep the value of work constant.

 

[Dark Destination]

According to Pure Physics, Work = Force * Displacement. Energy in the system is constant so work will remain the same. Since the force on the second piston is larger, the displacement will be smaller to keep the value of work constant.

Oh, i just stated that the piston had a greater area.
The oil is in compressible, so when the smaller piston moves a large distance, the larger piston will have to move a small distance to accommodate that same volume. :/

 

[Lilly2318]

How to get 15/15 in summary points? I always get 13 in school exams.

i gave u link several times
http://www.olevelpakistan.com/2012/09/149/
its of my teacher (who left)

 

[Zain Salman Dar]

If you're talking about the question where something was to be constant but not zero.. it wasn't acceleration.. As acceleration was zero..

the gradient of the graph was constant. gradient=acceleration(constant). if it was a speed/time graph :/

 

[Lilly2318]

Oh, i just stated that the piston had a greater area.
The oil is in compressible, so when the smaller piston moves a large distance, the larger piston will have to move a small distance to accommodate that same volume. :/

Do try not to regret . wahts done is done

 

[Dark Destination]

the gradient of the graph was constant. gradient=acceleration(constant). if it was a speed/time graph :/

Which question? MCQs?

 

[Zain Salman Dar]

if

the gradient of the graph was constant. gradient=acceleration(constant). if it was a speed/time graph :/

if the speed was same like any value for example 5 m/s then acceleration would be 0

 

[Lilly2318]

the gradient of the graph was constant. gradient=acceleration(constant). if it was a speed/time graph :/

wasnt it GPE cuz movng u the hill

 

[Zain Salman Dar]

Which question? MCQs?

MCQ

 

[Zain Salman Dar]

wasnt it GPE cuz movng u the hill

it was increasing but not constant, k.e was decreasing which was not constant.

 

[Dark Destination]

it was increasing but not constant, k.e was decreasing which was not constant.

They said moving up the hill at constant speed.

If the speed is constant, mass is constant, 1/2mv^2 is constant, so isn't kinetic energy constant?

 

[Zain Salman Dar]

They said moving up the hill at constant speed.

If the speed is constant, mass is constant, 1/2mv^2 is constant, so isn't kinetic energy constant?

when you are moving up a hill, gpe is increasing, k.e hence will decrease.

 

[Dark Destination]

when you are moving up a hill, gpe is increasing, k.e hence will decrease.

What were the options?
It can't be acceleration, as it was zero, when the speed was constant.

 

[Zain Salman Dar]

What were the options?
It can't be acceleration, as it was zero, when the speed was constant.

it can't be gpe,or ke or acc. Only option left is resultant force.