The force of air resistance $F$ on a car depends on speed $v$ through the formula $F=a{v}^2+bv$, where $a$ and $b$ are constants. Which of the following graphs will result in a straight-line graph?

The diagram shows the temperature of a liquid before and after heating.

Which is the best estimate for the temperature increase of the liquid?

A student wishes to measure the acceleration of free fall by letting a ping pong ball drop from one fixed height from the floor. He measures the height. Using a stopwatch, he measures the time for the ball to drop to the floor. He then uses the equation $h=\frac{1}{2}g{t}^2$ to calculate $g$.

State and discuss three improvements to the student's lab experiment.