Put a fork under your pillow tonight, and your wish will come true tomorrow.
Answer:
1.24 m/s
Explanation:
Metric unit conversion:
9.25 mm = 0.00925 m
5 mm = 0.005 m
The volume rate that flow through the single pipe is
This volume rate should be constant and divided into the 4 narrower pipes, each of them would have a volume rate of
So the flow speed of each of the narrower pipe is:
Answer:
3.71 m/s
Explanation:
From the law of conservation of linear momentum, since we are neglecting minor energy losses due to friction then we can express it as 
since all the potential energy is transformed to kinetic energy
Making v the subject of the formula then 
and here m is the mass of the block, g is acceleration due to gravity, h is the height. Substituting 0.7 m for h and 9.81 for g then we obtain that 
Answer:
Explanation:
If we assume there is a sharp boundary between the two masses of air, there will be a refraction. The refractive index of each medium will depend on the relative speeds of light.
n = c / v
If light travels faster in warmer air, it will have a lower refractive index
nh < nc
Snell's law of refraction relates angles of incidence and refracted with the indexes of refraction:
n1 * sin(θ1) = n2 * sin(θ2)
sin(θ2) = sin(θ1) * n1/n2
If blue light from the sky passing through the hot air will cross to the cold air, then
n1 = nh
n2 = nc
Then:
n1 < n2
So:
n1/n2 < 1
The refracted light will come into the cold air at angle θ2 wich will be smaller than θ1, so the light is bent upwards, creating the appearance of water in the distance, which is actually a mirror image of the sky.
Answer:
1.An element consists of the same kind of atoms while a compound is composed of different kinds of atoms.
2.A monoatomic element cannot be split up physically or chemically but a compound can be split up into new substances by chemical means.
3.Only limited number of elements are known in an element whiles number of known compounds are quite large.
4.The property of an element is the property of the atom whiles the property of a compound is quite different from that of it's constituents.
5 . Elements are represented by symbols and numbers.for example Sodium is represented by Na whiles compounds are represented by their chemical formula.for example,Salt is represented by the formula NaCl.
