9.) A 40-kg bookshelf requires a 200 N force to begin its motion. Once moving. It only requires a force of 50 N.
a. What is the normal force?
b. Determine the static coefficient of friction

What do elements in a family tend to share. a.) similar periods b.) similar groups c.) similar atomic symbols d.) similar chemical properties and characteristics

This is really important 1.which of the following prefixes represents the largest value? (2 points)gigahectorkilomilli2.which of the following types of graphs is best for plotting the mean, median, and mode of data? (2 points)bar graphbox-and-whiskercircle graphstem-and-leaf

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.