Answer
given,
mass of the piano = 170 kg
angle of the inclination = 20°
moves with constant velocity hence acceleration = 0 m/s²
neglecting friction
so, force required to pull the piano
F = m g sin θ
F = 170 × 9.81 × sin 20°
F = 570.39 N
so, force required by the man to push the piano is F = 570.39 N
The northern lights are shafts or curtains of colorful light that occasionally appear in the night sky. They are one of the numerous astronomical phenomena known as polar lights (aurora Polaris).This phenomenon may be observed in mars.
Earth's magnetic field directs electrons and protons from the sun to the poles, where they excite atmospheric gas molecules and cause them to glow, resulting in the aurora borealis and aurora australis, two nocturnal light displays. You might refer to it as the aurora Universalis on Mars. This is because Mars does not direct the energetic particles from the sun to its poles since it lacks an internal magnetic field. Today, researchers utilizing the MAVEN (Mars Atmosphere and Volatile Evolution) spacecraft find evidence for an aurora that may potentially cover the whole nightside of the planet. Venus lacks a magnetic field, thus it would not experience the same kind of nighttime aurora that we do.
To know more about aurora borealis go here:-
brainly.com/question/12757223
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Because the light from it travels to you about 874 thousand times
as fast as the sound does, so the hearing part falls behind the seeing
part.
