Cells have methods for breaking down proteins and other molecules that are no longer needed. These can then be removed from the cell. Why is this waste removal necessary? A. Cells must remove waste in order to keep other cell processes functioning properly. B. The waste products are necessary for new cells to be made. C. Cells must remove waste because it is used to extract energy from food. D. The waste products are necessary for respiration and photosynthesis in other cells.

Copper has free electrons per cubic meter. a 71.0-cm length of 12-gauge copper wire that is 2.05 mm in diameter carries 4.85 a of current. (a) how much time does it take for an electron to travel the length of the wire? (b) repeat part (a) for 6-gauge copper wire (diameter 4.12 mm) of the same length that carries the same current. (c) generally speaking, how does changing the diameter of a wire that carries a given amount of current affect the drift velocity of the electrons in the wire?

How to calculate voltage drop in a series circuit

A1000-kg car is moving at 30 m/s around a horizontal unbanked curve whose diameter is 0.20 km. what is the magnitude of the friction force required to keep the car from sliding?