Randall D. Knight — Dynamics I: Motion Along a Line: Problem 59

Astronauts in space 'weigh' themselves by oscillating on a spring. Suppose the position of an oscillating 75 kg astronaut is given by \(x = (0.30\text{ m})\sin((\pi\text{ rad/s}) \times t)\), where \(t\) is in s. What force does the spring exert on the astronaut at (a) \(t = 1.0\text{ s}\) and (b) \(t = 1.5\text{ s}\)? Note that the angle of the sine function is in radians.