Physics: Post your doubts here!

[Math Buddy]

From graph u can see its less than 2.55...

Yes, even i got 2.55..... using w= 0.5 kl^2 I just rounded it of to 2.6, anyways thanks i got it

 

[The Sarcastic Retard]

Yes, even i got 2.55..... using w= 0.5 kl^2 I just rounded it of to 2.6, anyways thanks i got it

when u have force to extension greaph, quick formula is 0.5Fx

 

[Hassansheikh]

I got two problems.

 

[princess Anu]

I got two problems.
View attachment 54874 View attachment 54875

What's the and for the 2nd one?

 

[The Sarcastic Retard]

I got two problems.
View attachment 54874 View attachment 54875

For q24 use I = P/A formula and use I prop to a^2 concept..

 

[princess Anu]

Q1. Ans Is A .. why is C wrong?



how to do Q17 & 11?

 

[nehaoscar]

Why C?
The current flows from left to right so to increase the current accross the sliding contact, shouldn't it be D??

 

[princess Anu]

ans is A :/

 

[DaniyalK]

ans is A :/View attachment 54892

Resistance = resistivity * (length/x-sectional area)
length is halved and area is doubled so resistance is 1/4th of the original.

 

[princess Anu]

Resistance = resistivity * (length/x-sectional area)
length is halved and area is doubled so resistance is 1/4th of the original.

but then why isn't this concept applicable here? here the ans is C, why ? :S how is it different?

 

[princess Anu]

HELP

Ans is C

 

[DaniyalK]

View attachment 54893

but then why isn't this concept applicable here? here the ans is C, why ? :S how is it different?

It's not the same. In the previous question, volume was same but length and area were different.
In this one, volume and length are both same.

 

[Studydayandnight]

HELPPP

Correct answer is C.

 

[princess Anu]

It's not the same. In the previous question, volume was same but length and area were different.
In this one, volume and length are both same.

Oh, I get it.. Thanks A lot
Can you try the others too please

 

[DaniyalK]

HELP

Ans is C

Driving force = ma = 1800 * 2 = 3600N
Tension in first cable from left = T0
Motion of powered vehicle:
3600 - T0 = 200(2)
T0 = 3200
Motion of cart 1:
T0 - T = 400(2)
T = 2400N

HELPPP

Correct answer is C.

Moment due to weight = 0.1 * 10 * 9.81 = 9.81 clockwise
Moment due to pulley = 0.02*9.81*60 = 11.77 anti cw
difference is 1.962 anti cw, so we need 1.962 in cw direction, which we get by placing 50g on the 44cm mark.

 

[princess Anu]

It's not the same. In the previous question, volume was same but length and area were different.
In this one, volume and length are both same.

help me with this pleaseee. Ans is A

 

[DaniyalK]

help me with this pleaseee. Ans is A View attachment 54896

KE = 0.5 * 50 * 3 * 3 = 225
mgh = 225
h = 0.46m
cos(theta) = 3.54/4

 

[nehaoscar]

How B??
Y = FL/AX
L halves and A is reduced by 1/4th so shouldn't it be C??

 

[nehaoscar]

How B??
strain is deltaL/L so it it that delta l is proportional to L?

 

[nehaoscar]

Why is resultant force zero?