T is the time for a whole round.
centripetal acceleration = V^2/R,
20 = 40^2 / R, find R = 40^2/20 = 40*40/20 = 80 m, right?
Now, one round is L = 2*pi*R = 2*pi*80 = 160*pi
And T = L/v (distance/speed) = 160*pi/40 = 4*pi seconds, or ~ 12.57 s
Answer:
The reflection and rectilinear propagation of light helps in the formation of shadows and also tells light doesn't penetrate opaque materials.
Answer:
M au = Fs - M g au = upwards acceleration; Fs = scale reading
Fs = M (au + g) scalar quantities where g is positive downwards and au is positive upwards - Fs is the net force acting on the person
If the acceleration is zero Fs = M g and the scale reads the persons weight
If the elevator is decelerating then au is negative and the scale reading Fs = (g - au) M and the scale reading is less than the weight of the person
