Carol and Dan run a 50 meter race along a straight horizontal track. They start at the same position at the same time. Carol runs with constant speed. During the race, Dan stops for a few seconds to tie his shoe. Other than this interruption, Dan runs with constant speed. They cross the finish line at the same time. Who has the larger average velocity for the whole race? Who has the larger speed when they cross the finish line?

Same average velocity, Dan has larger speed when crossing finish line.

Explanation:

Average velocity = displacement/time. Since they cross the finish line at the same time, the time is the same. Displacement is the change in position. Since they started at the same position and crossed the same finish line, displacement is also the same. So average velocity is the same for Carol and Dan.

Since Dan stops for a few seconds while Carol runs constantly, Dan has a faster speed since he has to make up for the 'lost' time.