A passenger of mass 72.2 kg

cbse
lawsofmotion

#1

A passenger of mass 72.2 kg is riding in an elevator while standing on a platform scale. What does the scale read when the elevator cab is (i) descending with constant velocity (ii) ascending with constant acceleration, 3.5 m/${{s}^{2}}$ ?


#2

Given, mass, m = 72.2 kg
Gravity acceleration, g = 9.8 m/${{s}^{2}}$ Scale reading = apparent weight = R = ?
(i) While descending with constant velocity, a =0
R = mg
R = 72.2 x9.8
=>R = 707.56 N
(ii) While ascending with a = 3.2 m/${{s}^{2}}$
R = m(g + a)
R = 72.2 (9.8 + 3.2) = 938.6 N