PHYSICS PPR 4!!!!

[jerry]

Help needed for these questions!!!!!
all are about oscillations!!!

ppr4...nov 04..Q3cii....my amplitude is cuming 4, but in the m.s its 4.5!!how???
jun 06...Q4ci and ii...dont understand where to mark!!!
nov 06...Q3a!!! please show clearly how to get the ans!!
nov 08..Q3bii..1 and cii!!

wud be thankful if someone is there to solve these qs

 

[beacon_of_light]

NOV 08 :
b(ii) 1 : In the question it is mentioned that the total vertical displacement is 22mm and you know that amplitude is half of total displacement. therefore, amplitude is 11mm.

c(ii): Now when the needle moves through the cloth, it moves through a vertical distance of 8mm. thereby, the vertical displacement would be 11 - 8 = 3mm...
You can draw a curve and confirm that!

 

[beacon_of_light]

NOV 06:

a = ω^2 x where w is omega or angular velocity ...

a = 2kx/m

equate both ....
2kx/m = ω^2 x

2k/m = w^2
w = 2 π f
2k/m = 4π ^2 f^2

Now solve and u'll get your answer

 

[beacon_of_light]

June 06 :

I think you should read this chapter once again thoroughly...

At mean position, displacement is zero but speed is maximum but at maximum displacement , speed is minimum...

 

[beacon_of_light]

NOV 04:

If 20% of energy is lost, the oscillations would have the remaining 80% of energy. The maximum Kinetic energy according to the graph is 12 mJ...
Now
maximum kinetic energy = 1/2 m ω^2 X^2 where X is the amplitude...
Now solve it.....

 

[jerry]

for june 06, i know all that, max disp, min vel..but what i meant was where exactly to mark on the wheel?like in the m.s they say mark on vertical line from the centre...which point??how do u know which part in max disp or wat??
and for N06..what spring constant did u use in the equation, .03Nm^-1 or 3Ncm^-1 coz im getting .08 hz instead of 8!!!

p.s thanks for all the explainations, really helped

 

[beacon_of_light]

Well If you remember we link circular motion and SHM to some extents... so consider a complete circle drawn as a single oscillations... You see the piston's mean position and the position of point on the circle...simply judge that and find your answer...

And always use SI units ... so it's 3N/cm or 300N/m ...ur conversions to /m are wrong!

 

[jerry]

thankssss alotttttt