A box of bananas weighing 40 N rests on a horizontal surface. The coefficient of static friction between the box and the surface is 0.4, and the coefficient of kinetic friction is 0.2. If no horizontal force is applied to the box and the box is at rest, how large is the friction force exerted on the box? A. 6 N
B. 8 N
C. 16 N
D. 0 N

Select for each of the following statements whether it is correct or incorrect. (a) in an isothermal expansion of an ideal gas. (b) the temperature remains constant. (b) the pressure remains constant. (c) there is work done by the gas. (d) there is heat added to the gas. (e) the change in internal energy equals zero.

Specific heat refers to the amount of heat required to change 1 gram of a substance by degree(s) celsius

Which of the following is part of the explanation or description of electromagnetic waves? (select all that apply) a. electrically charged molecules in a medium transfer their energy to nearby electrically charged molecules. b. a changing electric field causes a changing magnetic field. c. magnetic molecules in a medium transfer their energy to nearby magnetic molecules. d. a changing magnetic field causes a changing electric field.