Urgent help with Period of a pendulum!

1. Nov 12, 2012

riseofphoenix

#7.

T ≈ 2π√(L/g)

1.31 = 2π√(L/9.81)
1.31/2π = √(L/9.81)
2.057 = √(L/9.81)
2.057² = L/9.81
4.2343 = L/9.81
4.2343(9.81) = L
41.54/1000 = L
0.0415 = L

"INCORRECT: Your response differs from the correct answer by more than 100%. "

2. Nov 12, 2012

riseofphoenix

Wow where is everybody?

3. Nov 12, 2012

riseofphoenix

Hello?

4. Nov 12, 2012

SammyS

Staff Emeritus
One clue is the mention of the moment of inertia.

Another is that it's a physical pendulum.

Also,

5. Nov 12, 2012

riseofphoenix

I =T2MgD/4π2
I = [(1.312)(0.246)(9.81)(18)]/39.478
I = 74.545/39.478
I = 1.8882

"INCORRECT"

-___-
AKFJDJFDAKLNDJK

6. Nov 12, 2012

SammyS

Staff Emeritus
Convert centimeters to meters.

7. Nov 12, 2012

riseofphoenix

Oh...

0.0188

"CORRECT"

-.- The day I graduate from Webassign...........

Thank you...

#3. A 40.0-g object is attached to a horizontal spring with a force constant of 10.0 N/m and released from rest with an amplitude of 20.0 cm. What is the velocity of the object when it is halfway to the equilibrium position if the surface is frictionless?
m/s

8. Nov 12, 2012

SammyS

Staff Emeritus
Describe the motion of the object after being released.