If the box is moving at constant velocity, net force must be zero, so:
F + fr = 0
fr = -F
<u>fr = -40 N</u>
I haven't worked on Part-A, and I don't happen to know the magnitude of the gravitational force that the Sun exerts on the Earth.
But whatever it is, it's exactly, precisely, identical, the same, and equal to the magnitude of the gravitational force that the Earth exerts on the Sun.
I think that's the THIRD choice here, but I'm not sure of that either.
Answer: Longitudinal Waves
Explanation: The particles of the medium pass parallel to the course that the heart beat moves. This sort of wave is a longitudinal wave. Longitudinal waves are usually characterised through particle motion being parallel to wave movement. A valid wave traveling thru air is a classic example of a longitudinal wave.
It is D, a paint can carried up a ladder.
Im pretty sure this is A. i may be incorrect, give brainliest if im correct please!