Shubhangi_check_lab03_comment

Check_lab03.py > check_p02 does not work for me. Frequency values differ for specified density and Ypung's modulus.

Problem 2 - 
# your work here
E=210E9 # 70,000,000 Pa=70 GPa
b=2e-3 # width in m
t=6e-3 # thickness in m
I=b*t**3/12 # second moment of area for rectangular cross-section (m^4)
mbar=7800*b*t # 7500 kg/m^3*(cross-section area) -> mbar [kg/m]
L=300e-3 # length in m

f1=natural_frequency(1,E,I,mbar,L)
f2=natural_frequency(2,E,I,mbar,L)
f3=natural_frequency(3,E,I,mbar,L)
p.check_p02(f1/2/pi,f2/2/pi,f3/2/pi)

print('the 1st natural frequency is %1.3f Hz'%(f1/2/np.pi)) 
print('the 2nd natural frequency is %1.3f Hz'%(f2/2/np.pi)) 
print('the 3rd natural frequency is %1.3f Hz'%(f3/2/np.pi)) 

Output : 

Whoops, try again
the 1st natural frequency is 55.879 Hz
the 2nd natural frequency is 350.190 Hz
the 3rd natural frequency is 980.542 Hz