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?

The table shows test data for the Bugatti Veyron Super Sport, the fastest street car made. The car is moving in a straight line (the $x$-axis).

(a) Sketch a $v_x$-$t$ graph of this car's velocity (in mi/h) as a function of time. Is its acceleration constant?

(b) Calculate the car's average acceleration (in m/s2) between (i) $0$ and $2.1$ s; (ii) $2.1$ s and $20.0$ s; (iii) $20.0$ s and $53$ s. Are these results consistent with your graph in part (a)? (Before you decide to buy this car, it might be helpful to know that only $300$ will be built, it runs out of gas in $12$ minutes at top speed, and it costs more than $\$1.5$ million!)

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 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 decreasing in magnitude?

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 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?