Edexcel Physics Unit 1 January 2012

i wrote something like tht bt relating t newton's 3rd law

there was a question where it asked why the ball will travel over the net, what was your responses?

I wrote that the downward force arises from the high pressure/density area above the ball, since the air-flow was moving up...I think.

Well i guess i am the only one :O who found it easy
i got raped back in june

i am expecting an A this time thoe

The 2 mark question regarding the spinning ball just got me thinkin and em not sure bot it
else my calculations were all right (which never happnd when i practised papers)

I wrote something like the ball follows parabolic path from the bat to the point just before the net after that it rebounds and again follows parabolic path to the other side of the net. Since the question asked about how the direction of spin helps the ball i also said that the direction of spin is towards the direction of air flow where the flow was laminar as a result the ball moves with constant velocity through out its motion.
don't know if this is right.

I am not sure about the tennis ball question as well..
I said the ball needed turbulent flow for it to move from one region to another as it it moves at laminar flow then it would move straight, which is not the correct direction..
I said turbulent flow allows ball to move in eddies form from a region which has high pressure to a region where there is low pressure
Is this okkk ?

for the one where lawnmower. It requires greater force as the handle is horizontal and you are not applying any force at angle so requires greater force to push it.
Is this right?

for the question of turbine where it asks you to find the volume of air passing through the turbine in 5 seconds. the question after that where you are asked to find the mass of air are we expected to use the volume calculated in previous question in 5 seconds or to find the new volume just using 2000m2 and velocity which was in meters per second.
For the last bit of the same question related to turbine with 59% efficiency what did you guys do?
did you get answer some where around 1500W some zeros can't remember how many zeros?

Same here! i found the paper pretty ok as well... wasnt really bad..

WOHOOO
All the best

I has a serious time issue. I had about 30 mins to do about half of the paper so I just wrote a load of rubbish.

Whats the answer to the lawnmower one ??

the horizontal handle ?
Its cause its angle is reduced.
There still will be a vertical force acting also since the whole thing connected to the moer is in a diagonal.
So writting that theres the only force applied is horizontal is absurd.
So as far as i think its the angle is reduced

Well i guess i am the only one :O who found it easy
i got raped back in june

i am expecting an A this time thoe

The 2 mark question regarding the spinning ball just got me thinkin and em not sure bot it
else my calculations were all right (which never happnd when i practised papers)

How do you think it will effect the total horizontal force supplied towards the bottom of the handle?
I think that the new design of handle will need more force to move the same distance than the previous design.
Not sure of my answer though.

How many UMS are you expecting?
I should also easily get an A but my aim of getting 120/120 looks too far, so i will have to accept something in the range of 105-110.

for the one where lawnmower. It requires greater force as the handle is horizontal and you are not applying any force at angle so requires greater force to push it.
Is this right?

for the question of turbine where it asks you to find the volume of air passing through the turbine in 5 seconds. the question after that where you are asked to find the mass of air are we expected to use the volume calculated in previous question in 5 seconds or to find the new volume just using 2000m2 and velocity which was in meters per second.
For the last bit of the same question related to turbine with 59% efficiency what did you guys do?
did you get answer some where around 1500W some zeros can't remember how many zeros?