Biology; Chemistry; Physics: Post your doubts here!

[CoolBreeze]

no it is not good the force applied due to engine is 3000N. from the equation F=ma, we get the resultant force and for the resultant force to be 2000 the engine force must be 3000 so that 3000-1000=2000N. and if the engine force would have been 1000 then the resultant force would be zero and the car would have moved with a constant speed and acceleration would not have been possible!!!

Thanxxx...at last I understood what my teacher had explained with ALIEN formulas but the answer matches!!!!
So it's perfect
Thankxx alot

 

[ritesh isuri]

resultant force is sum of force.
force of engine is x
force of resistance is -1000N(opposite direction)
resultant force if 2000N
so, x+(-1000)=2000, x=3000N

at least someone has understood what i meant!!

 

[ritesh isuri]

Thanxxx...at last I understood what my teacher had explained with ALIEN formulas but the answer matches!!!!
So it's perfect
Thankxx alot

u r welcome!!!

 

[CoolBreeze]

How are cell membranes and plasma membrane different?

 

[CoolBreeze]

Is t true that cell membrane allows water to pass through osmosis but not other substances by simple diffusion?

 

[falcon678]

How are cell membranes and plasma membrane different?

they r one n same.....

Is t true that cell membrane allows water to pass through osmosis but not other substances by simple diffusion?

no it is not.....it allows water to pas throu osmosis n allows only those substances to pas throu wich r smal enough to pas throu it by diffusion!

 

[ritesh isuri]

How are cell membranes and plasma membrane different?

they are the same!!!

Is t true that cell membrane allows water to pass through osmosis but not other substances by simple diffusion?

well water can enter by osmosis and other small substances can also enter in by diffusion!! but its true that for osmosis to take place there must be a cell membrane or any partially permeable membrane whereas diffusion can take place in the presence or absence of a cell membrane

 

[CoolBreeze]

Does vacoule helps in turgidity of animal cells as well???

 

[MuslimGirl]

papers.xtremepapers.com/CIE/Cambridge International O Level/Biology (5090)/5090_s03_qp_6.pdf
Can someone please tell me,,,, where am i supposed to get it's Marking scheme....? :S :|

 

[CoolBreeze]

Can anyone please help me with part e)????
Please name the structure as well

 

[falcon678]

t

papers.xtremepapers.com/CIE/Cambridge International O Level/Biology (5090)/5090_s03_qp_6.pdf
Can someone please tell me,,,, where am i supposed to get it's Marking scheme....? :S :|

there's no marking scheme for tht...but u can tally ur ans with the examiner's report....!

 

[CoolBreeze]

pls check my questions!!!
And explain if wrong plzz!!!

 

[CoolBreeze]

 

[falcon678]

pls check my questions!!!
And explain if wrong plzz!!!View attachment 18940 View attachment 18941

dude the ans r correct...!

View attachment 18945 View attachment 18944

u want ans for em?

 

[CoolBreeze]

dude the ans r correct...!
u want ans for em?

Yes of course!!!

 

[CoolBreeze]

Can anyone answer these???
]

 

[ritesh isuri]

Can anyone please help me with part e)????
Please name the structure as well

it must be starch since it is a plant cell and in plant cell starch is used as a storage substance

 

[ritesh isuri]

View attachment 18945 View attachment 18944

u have not answered to this one!!

 

[MuslimGirl]

t
there's no marking scheme for tht...but u can tally ur ans with the examiner's report....!

ohkhay.... thanks

 

[ritesh isuri]

If the object were to stay in place then there would be no action to have a reaction to in the first place.
The third law applies given that an action has already taken place. Example if a ball is moved with 2N force, the friction force against it would be equal(2N) and opposite (stopping it) and the ball would eventually come to rest.

not necessary!! if the resultant force is zero the ball can still move but with constant speed!!