Gquestions 1 - 4 compute forces in the members of the 2d truss below. the truss has an overall height of 4 meters and an overall length of 12 meters (there are 8 members along the bottom which each are 1.5 meters long). if the member is in compression, use a negative sign in the answer to indicate compression. work in units of kj for forces but do not enter units. determine the force in member kj. kj =

FKJ = 0    (It does not work).

Explanation:

The truss has an overall height of 4 meters and an overall length of 12 meters (there are 8 members along the bottom which each are 1.5 meters long). If the member is in compression, use a negative sign in the answer to indicate compression. Work in units of kN for forces but do not enter units. Determine the force in member KJ.

Ax = 0    ⇒   Ix = 0

∑ MA = 0   (counterclockwise +)   ⇒   - 10*3 – 6*9 – 6*10.5 + Iy*12 = 0  

⇒  Iy = 12.25 N  (↑)

∑ Fy = 0   (↑)  

Ay – 10 – 6 - 6 + Iy = 0      ⇒    Ay = 10 + 6 + 6 - 12.25      ⇒    Ay = 9.75 N (↑)

∑ MK = 0   (counterclockwise +)   ⇒  - FHI*4 + Iy*3 = 0  

⇒  FHI = (Iy*3) / 4 = (12.25*3) / 4

⇒  FHI = + 9.1875 N  

Node I:  

∑ Fx = 0   (→)  

FRI*Cos (θ) - FHI = 0     ⇒   FRI = FHI / Cos (θ) = 9.1875 / (3/5) = 15.3125 N

⇒   FRI = - 15.3125 N

Now, for the section in the figure 2 shown we have

∑ Fx = 0   (→)

⇒   FKJ + FRI*Cos (θ) - FHI = 0    

⇒    FKJ = FHI - FRI*Cos (θ) = 9.1875 - 15.3125*(3/5)

⇒   FKJ = 0    (It does not work).

The answer is water molecules are split.cellular respiration and photosynthesis are complement  reactions to each other. these are reverse reactions. in cellular respiration glucose and oxygen yield water and carbon dioxide. so, when respiration begins,  glucose molecules are split. in the opposite reaction - in photosynthesis, carbon dioxide and water yield glucose and oxygen. thus,  when respiration begins, water molecules are split.

The answer is trial 3.