A 517kg piano is on the first floor that is 2.4m high. You lift it up and carry it to the 4th floor that is 19m above the ground. How much work did you when you carried the piano from the 1st floor to
the 4th floor?

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.