A ball moves in a straight line (the $x$-axis). The graph in Fig. E$2.9$ shows this ball's velocity as a function of time. What are the ball's average speed and average velocity during the first $3.0$ s?

Starting from the front door of a ranch house, you walk $60.0$ m due east to a windmill, turn around, and then slowly walk $40.0$ m west to a bench, where you sit and watch the sunrise. It takes you $28.0$ s to walk from the house to the windmill and then $36.0$ s to walk from the windmill to the bench. For the entire trip from the front door to the bench, what are your (a) average velocity? (b) average speed?

A physics professor leaves her house and walks along the sidewalk toward campus. After $5$ min, it starts to rain, and she returns home. Her distance from her house as a function of time is shown in Fig. E$2.10$. At which of the labeled points is her velocity constant and positive?

A physics professor leaves her house and walks along the sidewalk toward campus. After $5$ min, it starts to rain, and she returns home. Her distance from her house as a function of time is shown in Fig. E$2.10$. At which of the labeled points is her velocity zero?

A physics professor leaves her house and walks along the sidewalk toward campus. After $5$ min, it starts to rain, and she returns home. Her distance from her house as a function of time is shown in Fig. E$2.10$. At which of the labeled points is her velocity constant and negative?

A car is stopped at a traffic light. It then travels along a straight road such that its distance from the light is given by $x(t)=bt^2-ct^3$, where $b = 2.40$ m/s² and $c = 0.120$ m/s³. Calculate the instantaneous velocity of the car at $t=0$, $t=5.0$ s, and $t=10.0$ s.

A car is stopped at a traffic light. It then travels along a straight road such that its distance from the light is given by $x\left(t\right)=b{t}^2-c{t}^3$, where $b=2.40$ m/s² and $c=0.120$ m/s³. Calculate the average velocity of the car for the time interval $t=0$ to $t=10.0$ s.