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stira [4]
2 years ago
12

A star is moving toward the earth with a speed of 0.9 c (90% the speed of light). it emits light, which moves away from the star

at the speed of light. relative to us on earth, the speed of the light moving towards us (emitted by the star) is
Physics
1 answer:
Bad White [126]2 years ago
8 0
The speed of light is constant in ALL frames of reference. That is 2.9 x10^8 m/s (290,000,000 m/s). It is independent of the motion of the light source.
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Which situation would create a field like the one shown here? A. an interaction between two magnetic south poles B. an interacti
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A green laser pointer has a wavelength of 532 nm. what is the energy of one mol of photons generated from this device?
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3 0
2 years ago
flat block is pulled along a horizontal flat surface by a horizontal rope perpendicular to one of the sides. The block measures
Lelu [443]

Answer:

Answered

Explanation:

v= 1 m/s

A= 1 m^2

m= 100 kg

y= 1 mm

μ = ?

ζ= viscosity of  SAE 20 crankcase oil of 15° C= 0.3075 N sec/m^2

forces acting on the block are  

                                 F_s   ←    ↓     →F_f

                                                mg

N= mg

F_s=  shear force = ζAv/y        F_f= friction force = μN

now in x- direction F_s= F_f

ζAv/y  =  μN

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Now, to compensate this frictional force friction coefficient must increase

as v∝μ

7 0
2 years ago
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Semmy [17]
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