The answer would be B. Magnetic fields are invisible they cannot be directly observed
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
<span>It’s 2/5 MR^2 where M is mass and R is the radius of the bas</span>