Answer:
Astronauts have edibles in space they dont need to know the mass. Trick question
Explanation:
at the same distance behind the mirror
Answer:
a) A´= A
b) θ₁´ = 29º, θ₂´ = - 169º
, θ₃´ = -49º
Explanation:
In this exercise you are asked to give the magnitudes and angles of the vectors from another system of
reference
a) The magnitudes
The magnitude of a vector, the size of which is a scalar, this does not depend on the reference system, since it is obtained by subtracting the coordinates of the end point minus the coordinate of the origin of the vector
A = - x₀
if the vectors are measured in another reference frame
x_{f}´ = xx_{f}- U
x₀´ = x₀ -U
where U is the distance between the two reference frames
A´ = x_{f}´ - x₀´
we substitute
A´ = (x_{f} - U) - (x₀-U) = x_{f} - x₀
A´ = A
it does not change
b) Angles
The given angles are measured from the positive part of the x axis in a counterclockwise direction, it is asked to give these angles from the x axis
θ₁ = 29º
does not change
θ₁´ = 29º
θ₂ = 191º
we measure clockwise
θ₂´ = θ₂ - 360
θ₂´ = 191 - 360
θ₂´ = - 169º
θ₃ =311º
we measure clockwise
θ₃´ = 311 -360
θ₃´ = -49º
If you make the freebody diagram, you will see that the only forces in the vertical direction are the weight of the book, which is downward, and an unknowm force upward that is responsible to keep the book at rest.
That unknown force upward, that opposes the movement of the book, is the friction force of the wall on the book, which by the way is proportional to the push force that you exert on the book.
Then the answer is that the friction force on the book point is up.