Two objects attract each other gravitationally with a force of 3. 1×10−10 nn when they are 0. 55 mm apart. Their total mass is 4. 8 kgkg.

15. one purpose of the tread pattern on a tire is to a reduce tire wear. b. reduce traction c. allow water to flow away from the tire. d. look impressive.

Which statement correctly describes a step-up transformer? a. it increases the amount of electric energy available. b. it increases the voltage of an electric current. c. it changes direct current into alternating current. d. it has more loops of wire in its primary coil.

(a) assume the equation x = at^3 + bt describes the motion of a particular object, with x having the dimension of length and t having the dimension of time. determine the dimensions of the constants a and b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.) (b) determine the dimensions of the derivative dx/dt = 3at^2 + b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.)