An athlete runs along a straight corridor

PHYSICS · Subjective · AP · Physics 1: Algebra-based · Kinematics · Kinematics

Problem

An athlete runs along a straight corridor. At

t = 0\,\text{s}

she is at the origin. She reaches

x = 50\,\text{m}

t = 5\,\text{s}

, continues to

x = 90\,\text{m}

t = 10\,\text{s}

, then turns back and arrives at

x = 30\,\text{m}

t = 16\,\text{s}

. (i) Sketch the displacement–time graph for the motion. (ii) Calculate the magnitude and sign of the velocity during the interval

5\,\text{s}

10\,\text{s}

. (iii) Calculate the magnitude and sign of the velocity during the interval

10\,\text{s}

16\,\text{s}

. (iv) Determine the average velocity and the average speed for the entire

16\,\text{s}

period. (v) Explain why average velocity and average speed have different values in this situation.