Laws of Motion · Question 1

A person sitting inside an elevator performs a weighing experiment with an object of mass 50 kg. Suppose that the variation of the height y (in m) of the elevator, from the ground, with time t (in s) is given by y=8 [1+ ( 2 tT ) ], where T=40 s. Taking acceleration due to gravity, g=10 m/s2, the maximum variation of the object's weight (in N) as observed in the experiment is

Answer

2

Solution

Apparent weight W=m(g+a), where a= y.

= 2 T= 2 40 = 120 rad s-1, a=-8 2 t, amax= 8400=0.02 m s-2

Wmax-Wmin=m(2amax)=50 0.04=2 N

Answer: 2