# Posts by 007

Total # Posts: 11

**Language arts**

3 is wrong the good answers are 1=b 2=d 3=a 4=a

**Chemistry**

An atom emits a photon of wavelength 1.08 meters. What is the energy change occurring in the atom due to this emission? (Planck's constant is 6.626 × 10-34 joule seconds, the speed of light is 2.998 × 108 m/s)

**Mechanical Behavior of Materials**

3....MPa use this equation (sigma)max=(sigma)avg+R

**Mechanical Behavior of Materials**

Some help please. I really don't know what is my error

**Mechanical Behavior of Materials**

I am having problems with the first part. Because I found the deflection as: delta=((P*(l_AB)^2)*((3*(l))-l_AB))/(6*E*I) But l is not permitted, so I replaced l=0.95[m]. but I obtained a wrong answer. My deduction is correct? What is my error? Please, some help.

**Mechanical Behavior of Materials**

I worked with this equation: sigma=C_2*E_s*0.1^2 = 750000[Pa] Then for the energy: U=sigma*s_densification= 750000*0.8=600000[J/m^3] But the answer is incorrect. Also, I know that E=C_1*E_s*0.1^2 =15[MPa] But I don't know how can I use it. Some help please

**algebra**

A boy walked for 4 hours and cycled for 3 hours,covering a total distance of 74 kilometers,later he walked for 2 hours and cycled for 4 hours ,covering 82 kilometers,what were his average speed of walking and his average speed of cycling if his speed was constant in the two ...

**physics**

008

**physics**

Are you sure its 42?

**Economics**

Haha, I'm stuck on this one too.

**acids and alkalis**

thanx you helped me