Time taken for a message to sent from earth to reach the first astronauts is 140 second.
It takes about three days for a spacecraft to reach the Moon. in the course of that time a spacecraft travels at the least 240,000 miles 386,400 km that is the space between Earth and the Moon. The specific distance depends at the specific path selected.
The distance from earth to moon is approximately3.84*108m
So, the distance from earth to the astronauts is3.84*108m - 10500*103m =3.735*108m
The speed of light c = 2.99792458*108m/s
So, divided the distance from earth to astronauts by the speed off light,
3.735*108m/2.99792458*108m/s ˜1.25seconds
Divided the Pluto-earth distance by speed of light:
Hence, 4.2*1010m/2.99792458*108m/s = 140seconds
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Answer:
Explanation:
Given
length of wire 
change in length 
mass of wire 
Young's modulus for silver 
load on wire 

change in length is given by

Where A=area of cross-section




also wire is the shape of cylinder so cross-section is given by





Left and right to a point called ad focal point after passing through convex lens
6. 0N. This questions requires understanding of how friction functions. Friction is a resistive force, meaning it opposes the direction of any applied or unbalanced forces. The box in the question experiences no horizontal force, so there is no resistive force in response to it, making it 0N.
7. This question tests your understanding of static friction. Static friction only applies when an applied or unbalanced force is applied to an object which does not move. The static friction always equals the magnitude of the applied or unbalanced force component parallel to the surface which the object rests on. The question states that the crate starts to move only when the applied force exceeds 313N, so we use this value to determine the force of static friction. The additional info in the question pertaining to when the crate is moving is irrelevant when determining static friction (only relevant if determining kinetic friction). Knowing this we solve for the weight of the crate:
F = mg
F = (45)(9.8)
F = 441N = Normal Force
The weight of the crate is also equal to the Normal Force since the object rests on a horizontal surface and the applied force is horizontal as well. In this question, since the object is not moving at 313N of applied force, the magnitude of static friction equals the applied force:
Ff = μs * Fn
(313) = μs (441)
0.71 (rounded) = μs