Physics: Post your doubts here!

[student2]

the text bk says tht whn ice is melted energy frm surroundings will conduct into tjhe ice so "L" (latent heat of fusion) is underestimate. bt y can't v say tht energy frm heater is lost 2 surroundings? pls any1?

 

[Sharukh khan]

can any one explain this beacuse according to me centripetal force = gravitational force So why he is asking same question and why are there 2 difffrent asnswers?

 

[Sharukh khan]

also iam confused in last 2 parts bcz accroding to me . reading on newton meter=9.8 into mass but this not the answer

 

[kanwal1]

can someone please explain this
9702/41/M/J/16 Q6 complete

 

[rahimshah98]

Hey guys, how many significant figures shoud our answers in P4 be?
Same as the least number of s.f in the raw data?

 

[Cadence]

3

Hey guys, how many significant figures shoud our answers in P4 be?
Same as the least number of s.f in the raw data?

 

[techgeek]

Someone pleeassse explain these sketches. MS says smooth curves and I'm not getting how!

 

[amina1300]

Can anyone give me some tips for my Alevels physics practical? I have 7 days till my practical and I did only 5-6 practicals in school which were basically not related to the any spring or electricity questions so... I dont have much hands on experience.

 

[Rizwan Javed]

Someone pleeassse explain these sketches. MS says smooth curves and I'm not getting how!
View attachment 62119

For the first one, if you see the equation for electric potential which is V = Q/(4*pi*e*r) you can easily see that V is inversely proportion to 'r'. So when 'r' is double, V is halved. The electric potential remains same (constant) till R. Then after that when R is doubled, V is halved, so the curve must pass through (R, Vs) & (2R, 0.5Vs).

Do the same thing with the next graph.

 

[techgeek]

For the first one, if you see the equation for electric potential which is V = Q/(4*pi*e*r) you can easily see that V is inversely proportion to 'r'. So when 'r' is double, V is halved. The electric potential remains same (constant) till R. Then after that when R is doubled, V is halved, so the curve must pass through (R, Vs) & (2R, 0.5Vs).

Do the same thing with the next graph.

Yeah thanks..
I got that too
btw how did we have to sketch that graph in paper about Hall voltage?

 

[student4563543]

A truck of mass 500kg moves from rest at the top of a section of track 400 m long and 30 m high, The frictional force acting on the truck is 250 N throughout its journey.What is the final speed of the truck? Help please. this is from october november 2016 varient 1 answer should be 14ms-1

 

[Enferno]

A truck of mass 500kg moves from rest at the top of a section of track 400 m long and 30 m high, The frictional force acting on the truck is 250 N throughout its journey.What is the final speed of the truck? Help please. this is from october november 2016 varient 1 answer should be 14ms-1

Total Initial Energy=Energy Wasted + Final Energy
The truck starts from rest so :
Potential Energy=Frictional Energy + Kinetic Energy
m*g*h = F*d + 0.5 * m*v^2
500*10*30=250*400 + 0.5*500*v^2
150,000 - 100,000=250*v^2
v^2= 200
hence
v = 14.1 ms-1

 

[techgeek]

won't it be too fast to measure period of such oscillations?
how do we do it then?

 

[selrey]

won't it be too fast to measure period of such oscillations?
how do we do it then?View attachment 62163

I am not quite sure, but our teacher told us that for such qs measure time and number of oscillations performed during that time and then divide the total time taken by the number of oscillations. And repeat the experiment atleat twice and then take an average of the times taken.

 

[selrey]

Also guys I have phy p3 tomorrow and i wanted to confirm if (in qs 1) we could put the values we recorded and caculated im first part of the question, in the table we are asked to make? Or we have to take new readings?

 

[amina1300]

Also guys I have phy p3 tomorrow and i wanted to confirm if (in qs 1) we could put the values we recorded and caculated im first part of the question, in the table we are asked to make? Or we have to take new readings?

We have to use that value too. 1---5 so 6 in total.

 

[selrey]

We have to use that value too. 1---5 so 6 in total.

I seeee. Thankyouu xx

 

[Zaki ali asghar]

any more tips for physics 33 tomorrow?

 

[selrey]

any more tips for physics 33 tomorrow?

Revise some of the ms for errors and improvements. It might help.

 

[GarryTheGhost]

apparently if you're doing paper 33 then you're going to do oscillations and...... scale balances what ever that means