Pleasecan someone help with this question in physics?


A uniform meter rule of mass 90g is pivoted at 40cm mark. If the rule is in equilibrium with an unknown mass M placed at the 10cm mark and 72g mass at the 70cm mark, determine M?



Pls if possible try solving it on screen(i am using a small phone and it does not zoom if pictures were posted)thanks.

The metre rule has only vertical masses acting on it.

mass M is 0.1m from zero of the metre rule but 0.3m away from the pivot (P).
the pivot (P) is 0.4m away from zero.
the metre rule's mass(90g) will act at the centre (0.5m from zero).
a 72g mass is 0.7m from zero.
Sum of moment about the pivot (P). with clockwise as positive=zero(condition for equilibrium);
[-M*0.3(M is 0.3m away from P)]+[90*0.1m(90g is 0.1m away from P)]+[72*0.3(72g is 0.3m away from P)]=0
Hence, M = 102g

captainbangz:
The metre rule has only vertical masses acting on it.

mass M is 0.1m from zero of the metre rule but 0.3m away from the pivot (P).
the pivot (P) is 0.4m away from zero.
the metre rule's mass(90g) will act at the centre (0.5m from zero).
a 72g mass is 0.7m from zero.
Sum of moment about the pivot (P). with clockwise as positive=zero(condition for equilibrium);
[-M*0.3(M is 0.3m away from P)]+[90*0.1m(90g is 0.1m away from P)]+[72*0.3(72g is 0.3m away from P)]=0
Hence, M = 102g

Very lucid sir am very grateful.

Pls help give same clear explanation on this.......

A uniform meter rule AB is balanced on a knife edge which is 55cm from B. If a mass of 10g is hung at P which is 10cm from A. Calculate the mass of the meter rule.

Also in the first question you solved why did you convert lengh to SIunits and did not do the same for mass?
Pls don't be bothered thank you.

IQvectors:



Very lucid sir am very grateful.

Pls help give same clear explanation on this.......

A uniform meter rule AB is balanced on a knife edge which is 55cm from B. If a mass of 10g is hung at P which is 10cm from A. Calculate the mass of the meter rule.

Also in the first question you solved why did you convert lengh to SIunits and did not do the same for mass?
Pls don't be bothered thank you.

(45-10)x10=(55-50)xmass
35×10=5mass
Mass of meter rule=70g

IQvectors:



Very lucid sir am very grateful.

Pls help give same clear explanation on this.......

A uniform meter rule AB is balanced on a knife edge which is 55cm from B. If a mass of 10g is hung at P which is 10cm from A. Calculate the mass of the meter rule.

Also in the first question you solved why did you convert lengh to SIunits and did not do the same for mass?
Pls don't be bothered thank you.

The Knife Edge(KE) is 55cm from point B, i.e 45cm from point A.
The mass of the meter rule M will be acting mostly in its(the metre rule's) centre(50cm away from whichever point), but 5cm away from KE.
The mass(10g) is 10cm away from A, i.e 35cm to KE.
Total sum of moment about KE=0(condition for equilibrium)[taking clockwise moment as positive].
= -10g*35cm+M*5=0
Hence, M=70g.
as Mrshape has above.

Mrshape:
(45-10)x10=(55-50)xmass 35×10=5mass Mass of meter rule=70g

thank you very much sir

captainbangz:

The Knife Edge(KE) is 55cm from point B, i.e 45cm from point A.
The mass of the meter rule M will be acting mostly in its(the metre rule's) centre(50cm away from whichever point), but 5cm away from KE.
The mass(10g) is 10cm away from A, i.e 35cm to KE.
Total sum of moment about KE=0(condition for equilibrium)[taking clockwise moment as positive].
= -10g*35cm+M*5=0
Hence, M=70g.
as Mrshape has above.

Thank you very much sir for this.

captainbangz:

The Knife Edge(KE) is 55cm from point B, i.e 45cm from point A.
The mass of the meter rule M will be acting mostly in its(the metre rule's) centre(50cm away from whichever point), but 5cm away from KE.
The mass(10g) is 10cm away from A, i.e 35cm to KE.
Total sum of moment about KE=0(condition for equilibrium)[taking clockwise moment as positive].
= -10g*35cm+M*5=0
Hence, M=70g.
as Mrshape has above.

sir please could yo help with this?

The lenght of a displaced pendulum bob which passes it lowest point twice every second is?

IQvectors:


sir please could yo help with this?

The lenght of a displaced pendulum bob which passes it lowest point twice every second is?

Just post all your questions at once.

Hahjascho:
Just post all your questions at once.

i was actually reading the topic yesternight and i got stock there.

IQvectors:


sir please could yo help with this?

The lenght of a displaced pendulum bob which passes it lowest point twice every second is?

Sorry to say, but I can't Sir.

IQvectors:


sir please could yo help with this?

The lenght of a displaced pendulum bob which passes it lowest point twice every second is?

Period equal 2sec because from the lowest point to the highest point is quarter circle.
T=2π√(L/g)

IQvectors:


sir please could yo help with this?

The lenght of a displaced pendulum bob which passes it lowest point twice every second is?

In a pendulum experiment the movement of the Bob from the lowest point to one end of the highest point back to the lowest point is half circle, so from the question it shows that half circle is done in 1 sec but period is the time taken to complete a full circle,
So the time to complete a full circle is 2secs.
Using your formula for period of a simple pendulum

T=2π√(L/g)
2=2π√(L/g)
(1/π)²=L/g)
L=(g/π²) meters.
This is the correct solution I know many textbooks and pass questions failed to solution to this question.
Again this is the correct solution

Mrshape:

In a pendulum experiment the movement of the Bob from the lowest point to one end of the highest point back to the lowest point is half circle, so from the question it shows that half circle is done in 1 sec but period is the time taken to complete a full circle,
So the time to complete a full circle is 2secs.
Using your formula for period of a simple pendulum

T=2π√(L/g)
2=2π√(L/g)
(1/π)²=L/g)
L=(g/π²) meters.
This is the correct solution I know many textbooks and pass questions failed to solution to this question.
Again this is the correct solution

thankyou very much sir my pastquestion did'nt give me this answer and that was why i was confused and dicided to post it here so some one could put me through .

Again many thanks for this sir.