2. 1D Motion / Kinematics

Julie drives 100 mi to Grandmother's house. On the way to Grandmother's, Julie drives half the distance at 40 mph and half the distance at 60 mph. On her return trip, she drives half the time at 40 mph and half the time at 60 mph. What is Julie's average speed on the way to Grandmother's house?

Which two physical quantities are combined to define $v$ (velocity)?

You normally drive on the freeway between San Diego and Los Angeles at an average speed of $105$ km/h ($65$ mi/h), and the trip takes $1$ h and $50$ min. On a Friday afternoon, however, heavy traffic slows you down and you drive the same distance at an average speed of only $70$ km/h ($43$ mi/h). How much longer does the trip take?

Which of the following best describes what $speed$ measures?

Which of the following factors applies to $v$ (velocity) but not to $s$ (speed)?

A cross-country skier completes a $7.5$ km race in $45$ minutes. What is the skier's average speed in $\text{km}/\text{h}$?

A particle moves in a straight line such that its velocity changes from $0$ to $40.0m/s$ in the first $20.0s$. What is the average acceleration $a_{\mathrm{av}}$ of the particle over this time interval?

Which of the following is the main difference between speed and velocity?

Which of the following best describes the difference between $speed$ and $average speed$?

Which of the following does $v$ describe?

A wave travels an average distance of $6m$ in $1s$. What is the wave's average velocity?

Corey Kluber throws a fastball at $93$ miles per hour. What is the speed of his fastball in feet per second?

Which of the following best describes the difference between $v\_\mathrm{avg}$ (average speed) and $v\_\mathrm{inst}$ (instantaneous speed)?