- #1

brownie24

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## Homework Statement

A platform on Earth rotates at constant angular speed 2 rad/s. A 60 kg man stands on the platform. Static friction between the platform and the man's feet prevent slipping.

(a) Make a diagram showing the forces he exerts on the platform standing a distance r from the axis of rotation. r = 0, 1, 2

(b) What direction does the man sense as "up"? Calculate the angle that "up" makes with the vertical using values of r as stated.

(c) If plants were planted on the platform, in what direction would they grow?

## Homework Equations

a = omega^2 r

## The Attempt at a Solution

(a) In the x plane, force of friction acts as force of centripetal acceleration = m omega^2 r. What I don't understand is what is the reactive force?

In the y plane, normal force opposes gravitational force = mg. If this is so, the man's weight should be constant, despite his distance from the rotational axis. Is (a) a trick question?