14. Which of the following ideas is NOT a part of cell theory? A. There are only plant and animal cells
B. All living things contain at least one cell
C. Cells come from other cells of the same kind
D. Cells are the basic unit of structure and function of living things

What property is a characteristic of a substance that can be observed and does not change the identity of the substance

Who was the first scientist to measure speed as distance over time?

Asled is being held at rest on a slope that makes an angle θ with the horizontal. after the sled is released, it slidesa distance d1 down the slope and then covers the distance d2 alongthe horizontal terrain before stopping. find the coefficient ofkinetic friction μk between the sled and the ground, assumingthat it is constant throughout the trip. find the coefficient of kinetic frictionμk. express your answer in terms of someor all of the variables d1, d2, and θ.