Question

At the bow of a ship on a stormy sea, a crewman conducts an experiment by standing on a bathroom scale. In calm waters, the scale reads 178 lblb . During the storm, the crewman finds a maximum reading of 225 lblb and a minimum reading of 133 lblb .

Find the magnitude of the maximum upward acceleration experienced by the crewman.

Find the magnitude of the maximum downward acceleration experienced by the crewman.

Answer 1

Given,

The weight in calm water, W = 178 lb

The maximum weight, W _max  = 225 lb

The minimum weight, W_min = 133 lb

a)

The maximum upward acceleration is,

By using force balance on crewman in vertical direction,

F = (W_max - W)

m a = (W_max - W)

a = (W_max - W) / m

where, is the mass of a crewman, m = W /g

a = (W_max - W) * g / W

a = (225 - 178) * 9.8 / 178

a = 2.59 m/s²

b)

The maximum downward acceleration is

F = W_min - W

- m a = W_min - W

a = (W - W_min ) / m

a = ( W - W_min ) * g / W

= (178 - 133) * 9.8 / 178

= 2.48 m/s²