A toy cannon launches a 46-g golf ball straight up into the air with a kinetic energy of 6.8 J. What must the
ball's velocity be as it leaves the cannon?
A. 0.54 m/s
B. 0.79 m/s
C. 17 m/s
D. 80 m/s

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.

Often called simply "velocity," this is the velocity of an object at a particular moment in time.

The radius of an atom is closest in size to a