Liza is pulling a wagon across the floor in a straight line at a constant speed of 3 m/s. If Liza is pulling with 20 N applied force on the box, what is the direction and magnitude of the frictional force on the wagon?

Atomic nuclei of almost all elements consist of

Glass has a hardness that is in the middle of the hardness scale. what is the hardness of glass?

Greg drew a diagram to compare two of the fundamental forces. which labels belong in the areas marked x, y and z? gravitational force electromagnetic force x. attractive y repulsive z: infinite range x: infinite range y attractive z. repulsive x. always attractive y: infinite range z: attractive or repulsive x. attractive or repulsive y infinite range z: always attractive