A river flows north at 4 m/s and a boy swims straight across it at 2 m/s. If the river is 8 m wide, how far will the boy be from
his starting point after crossing the river?

Aperson walks first at a constant speed of 4.89 m/s along a straight line from point a to point b and then back along the line from b to a at a constant speed of 2.95 m/s. what is the average speed over the entire trip?

An object resting on a table weighs 100 n. with what force is the object pushing on the table? with what force is the table pushing on the object? explain how you got your answer.

If two parallel light rays hit a mirror, they will not be parallel to each other after they reflect.