Edexcel IAL Physics Unit 1 WPH01 May June 2016 Discussion

I wrote plot a graph of velocity against radius^2 then find the gradient of the graph, i conapred the eqution of v=2gr^2(density of solid-density of fluod)/9n then compare it with y=mx+c so the gradient will be equal to 2g(Ps-Pf) then substistute values and get viscosity.

I wonder how did you guys get that answer of 500J question? Cos the line is curved, I didn't even know how to get the area under the graph.

I wonder how did you guys get that answer of 500J question? Cos the line is curved, I didn't even know how to get the area under the graph.

Do you think I'll get the mark if I say r squared against velocity. And then I wrote the gradient accordingly. I know Indepedant is supposed to be on the x axis but still?

yeah you should get the mark.. I also said plot a graph of v against r^2.. then compare the equation for viscosity with y=mx+c.. then simply substitute m with eta( n )

I wonder how did you guys get that answer of 500J question? Cos the line is curved, I didn't even know how to get the area under the graph.

The ball question 2nd part.Horizontal velocity.

Btw for time did u multiply by 2?

Why?

How did u guys show the distance is about 0.4 m in that bouncing ball ques....

Time we got was from x to y for the previous motion part it would be same so total will be 2xt

I did something else,Though I made a mistake I believe I took the time of 24 bounces instead of 20.24/20=1.2s.If I recall correctly You shouldn't be able to use that time between X and Y multiplied by 2.
EDIT:But I guess you've taken a certain distance? I just took the whole horizontal distance for 24 images.

I took distance between 2 balls on floor from ruler and used s=ut+1/2at2 where u was zero as from x to y and s was 0.44m so I fot time between x and y so I multiplied by 2 for whole projectile motion then I used speed=d/t where d was horizontal distance and I got 0.38ms-1 is it correct

Honestly,I don't know I barely remember the values I took.

For everyone asking about the ball question, here is what i did: For the first question to find the maximum height, the time was 6/20 because 20 was 1 second. And then use of equation s=ut+1/2at^2 because initial is zero as it falls from maximum height, all gpe no ke. You should get around 0.44m. Then for the second part, use the picture, if 0.44 was actual height, 6 cm was height on picture, that means total length(horizontal) was 9.3 cm. Convert both cm to meter. Use: If 6cm is 0.44m what is 9.3cm. You should get horizontal distance is 0.682m. Then use simple distance/time. Time for total should be 20/20 is 1 second and + 4/20 as it was 24 pictures and 20 was one second, so you need to add the extra 4, time should be 1.2. So velocity is 0.568m/s, atleast this is what i got, hopefully, it's correct.

From where does this multiplying the time by 2 comes from?..we were dealing with just the fall of the ball i.e (from x to y)..its not like the ball moving up and coming down so there is no point of doing anything with the flight time..just imagine it as if the ball has fallen from a roof and we are told to workout now..