Four runners compete in a 100 m race. The table shows the time it took for each runner to finish the race.
Runner
Kent
Shaun
Cal
Faith
Time (s)
14
17
15
13
a. i. Who came last in the race?
ii. Explain how you could tell.
b. i. What is the formula for working out speed?
ii. What is Cal's speed during the race?

Arunner is training for an upcoming marathon by running around a 100-m-diameter circular track at constant speed. let a coordinate system have its origin at the center of the circle with the x-axis pointing east and the y-axis north. the runner starts at (x, y) = (50 m, 0 m) and runs 2.5 times around the track in a clockwise direction.

Two steel balls, each of mass m, are welded to a light rod of length l and negligible mass and are initially at rest on a smooth horizontal surface. a horizontal force of magnitude f is suddenly applied to the rod as shown. determine (a) the instantaneous acceleration a of the mass center g and (b) the corresponding rate at which the angular velocity of the assembly about g is changing with time.

What happens to an isotope during radioactive decay?