The impeller of a centrifugal fan is 320 mm in diameter and has backward curved blades. at a speed of 1460 rev/min the fan delivers 1,5 m3/s of air (rho = 1,2 kg/m3) against a total pressure of 350 pa. the manometric efficiency at this duty point is 60% and the whirl velocity at the impeller exit can be assumed to be twice the impeller peripheral velocity. taking the mechanical efficiency as 90%, calculate the power required to drive the fan

wire in brush may conduct electricity from cell to drill and vice versa electrc shock possible

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

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im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27

blue light is scattered in different directions by the tiny molecules of air. blue is scattered more than other colours because it has a shorter distance to travel which results in smaller waves. this is why we see a blue sky most of the time.