Looks are sceptical! 2

Classical Mechanics Level 5

A Solid metallic cylinder of mass $m = 1\text{ kg}$ and $R = 20\text{ cm}$ is free to roll (without sliding) over the inclined surface of a wooden wedge of mass $M = 0.28\text{ kg}$ . Surface of wedge is inclined at an angle 37 degree with the horizontal and wedge lies on a smooth horizontal floor.

when the system is released from rest, calculate the angular acceleration of cylinder in $\text{rad/sec}^2$ .

Take g = 10 SI units

sin(37) = 3/5

cos(37) = 4/5

The answer is 30.

2 solutions

A Former Brilliant Member
Dec 12, 2016

easy peasy ...............one of the easiest level 5 problems i solved recently ,

bhai @Prakhar Bindal ek ques batade chem ka .....phenol reacts with dil. hno3 ...i wrote in paper that uski oxidation hogi but my teacher crossed it and wrote nitration hogi .....3 no.. gaye tu kya sochta hai plz tell... there was no h2so4 !

A Former Brilliant Member - 4 years, 6 months ago

Bhai dekh mere hisaab se tujhe nitration karani chahiye thi(although by incorrect concept)

You cannot oxidise phenol unless you oxidise benzene ring. that is not possible with dilute HNO3
If in school then they dont go into that much depth of the concept. agar main teri jagah hota to nitration karata. we cant argue with him because its not a carbon chain which can be oxidised . so according to me Nitration was the best answer to that!

Prakhar Bindal - 4 years, 6 months ago

thank you bhai..... bas ek aur.....A aur B elements make AB2 and AB4 ,they r dissolved in bezene , and we had to find depression in freezing point .... i said that an't hoff factor has to be 1 as you can't even think of dissociation in benzene .... it's aprotic solvent ....but my friends say it would be 3 and 5 , what do you say ??

A Former Brilliant Member - 4 years, 6 months ago

@A Former Brilliant Member – Actually it depends a lot. your statement is a bit wrong that in benzene dissociation and association dont take place.

In Case of Acetic acid dimerization takes place only in benzene on the account of hydrogen bonding possible in benzene but not in water.

Prakhar Bindal - 4 years, 6 months ago

@Prakhar Bindal – no i only said about dissociation ! bro , nothing was given about association , and i believe dissociation can not occur , so , van't hoff factor - 1 , am i wrong now ? plz tell @Prakhar Bindal

A Former Brilliant Member - 4 years, 6 months ago

Good q @Prakhar Bindal

Spandan Senapati - 4 years, 4 months ago

thanks!!!!

Prakhar Bindal - 4 years, 4 months ago

Aryan Goyat
Apr 27, 2016

just use the following

1)net horizontal acc of cm is 0

2)observe while in inclined and write a=(alpha)R

3)while in inclined find N and f.and then find net horizontal force on M and write net force=Ma alpha comes out 30

Actually bro answer is exactly 30 on taking g = 10!

Prakhar Bindal - 5 years, 1 month ago

yep i got my mistake (silly mistake are really hard to find )