Biology; Chemistry; Physics: Post your doubts here!

[Fate0]

Can someone tell me the mcq for that 'Constant but not zero' from the graph?

Resultant Force, seemed the only possible option.
NVM kinetic energy tha i think.

 

[Mazin Junaid]

Kinetic energy I thin

Can someone tell me the mcq for that 'Constant but not zero' from the graph?

think Option C

 

[sameersuleman]

4 Consecutive "a" and "c" ..., made my day... Btw i took it in N/m2 is it wrong... dont we find distance like this in distance time graph???

 

[Laibaaa]

Area under graph.
Triangle + Rectangle.
1
- x 3 x 2.4 + 5 + 2.4
2

The answer was 33.33 for N/cm and and was something big in 3's for the N/m one/

There were four consecutive "a" answers as well as four consecutive "c" answers,

Wait for the pressure one I wrote 33.33Pa. Pascals, is that okay?

 

[DaniyalK]

It was area of triangle + area of rectangle. (1/2 * 2.4 * 3) + (5*2.4) = 15.6.
You could do it in both N/cm^2 and Pa.
Constant but not zero was K.E

 

[sameersuleman]

It was resultant because either GPE and KE decreased/increased together... the total was same in my belief...

 

[DaniyalK]

It was resultant because either GPE and KE decreased/increased together... the total was same in my belief...

The car was travelling at a constant speed (forward force = backward force) so resultant was zero.

 

[Fate0]

It was resultant because either GPE and KE decreased/increased together... the total was same in my belief...

It cant be resultant because the car was moving with uniform speed. Thus resultant will be 0.

 

[Fate0]

Wait for the pressure one I wrote 33.33Pa. Pascals, is that okay?

I did the same thing xD But they'll cut down the Pa i think and deduct one mark, maybe, maybe not if they're merciful.

 

[DaniyalK]

For the answer mark, you have to give the right unit, so it will be just 1 mark deduction.

 

[Laibaaa]

I did the same thing xD But they'll cut down the Pa i think and deduct one mark, maybe, maybe not if they're merciful.

But why, pressure is measured in Pascals isn't it

 

[sameersuleman]

33.33 or 333333.3 ..... come on people ...

 

[Laibaaa]

It cant be resultant because the car was moving with uniform speed. Thus resultant will be 0.

I chose acceleration for that. I think its kinetic maybe now.

 

[M.Omar]

it said to define "efficiency"
not "percentage efficiency"
i think

Then they wud not have mentioned 75% intead 0.75........
they also mentioned efficiency as 75% and not percentage efficiency as 75%...
So it wud be more concise to mention abt the percentage conc in it and all tht..I do concur tht 1 pt is for useful energy or power obtained and other for ratio(multiplied by 100%)

 

[DaniyalK]

But why, pressure is measured in Pascals isn't it

If you did not convert the area from cm^2 to m^2, the answer should have been in N/cm^2. Pa is N/m^2.

 

[Mazin Junaid]

4 Consecutive "a" and "c" ..., made my day... Btw i took it in N/m2 is it wrong... dont we find distance like this in distance time graph???

I did the same and its right cause I wrote it in Pa which is N/m²....Also the force you get for the larger piston is same if you took both as N/cm² orN/m2

 

[sameersuleman]

I did the same and its right cause I wrote it in Pa which is N/m²....Also the force you get for the larger piston is same if you took both as N/cm² orN/m2

btw how much was the pressure?

 

[Laibaaa]

For the second last question, the heat capacity one,
the mass was o.50 kg right ?

 

[asadalam]

For the second last question, the heat capacity one,
the mass was o.50 kg right ?

Yup

 

[Lilly2318]

Ok i got confused in first parts. i thought they were equal but then i said that forward was more cuz lorry was moving/accelerating in forward direction. and in backwrd force i wrote friction :/ . how many marks am i losing here