Answer:
28.8 cm
Explanation:
Magnification in a microscope is:
M = Mo * Me
Where
Mo: magnification of the objective,
Me: Magnification of the eyepiece.
The magnification of the objective if:
Me = npd/fe
Where:
npd: near point distance
fe: focal length of the eyepiece
The magnification of the objective:
Mo = d/fo
Where
d: the distance between lenses
fo: focal length of the objective
Then
M = npd/fe * d/fo
d = M * fe * fo / npd
d = 12 * 5 * 12 / 25 = 28.8 cm
Explanation:
formation of compounds because the electric forces compel the atoms to attract each other and formed bonds which leads to the formation of chemical compounds. The attractive or repulsive interaction between any two charged bodies is known as an electric force so the attraction between two opposite charged atoms causes the formation of compounds so we can conclude that electric forces are important for the formation of compounds.
Answer:
v ’= 21.44 m / s
Explanation:
This is a doppler effect exercise that changes the frequency of the sound due to the relative movement of the source and the observer, the expression that describes the phenomenon for body approaching s
f ’= f (v + v₀) / (v-)
where it goes is the speed of sound 343 m / s, v_{s} the speed of the source v or the speed of the observer
in this exercise both the source and the observer are moving, we will assume that both have the same speed,
v₀ = v_{s} = v ’
we substitute
f ’= f (v + v’) / (v - v ’)
f ’/ f (v-v’) = v + v ’
v (f ’/ f -1) = v’ (1 + f ’/ f)
v ’= (f’ / f-1) / (1 + f ’/ f) v
v ’= (f’-f) / (f + f’) v
let's calculate
v ’= (3400 -3000) / (3000 +3400) 343
v ’= 400/6400 343
v ’= 21.44 m / s