Which statement best describes a difference between the trachea and the esophagus?
The trachea is a long, hollow tube, and the esophagus is a small, kidney-shaped organ
The trachea is part of the digestive system, and the esophagus is part of the respiratory system
The trachea delivers oxygen through the body, and the esophagus releases carbon dioxide
The trachea allows for the passage of air, and the esophagus allows for the passage of food

Part f - example: finding two forces (part i) two dimensional dynamics often involves solving for two unknown quantities in two separate equations describing the total force. the block in (figure 1) has a mass m=10kg and is being pulled by a force f on a table with coefficient of static friction îľs=0.3. four forces act on it: the applied force f (directed î¸=30â above the horizontal). the force of gravity fg=mg (directly down, where g=9.8m/s2). the normal force n (directly up). the force of static friction fs (directly left, opposing any potential motion). if we want to find the size of the force necessary to just barely overcome static friction (in which case fs=îľsn), we use the condition that the sum of the forces in both directions must be 0. using some basic trigonometry, we can write this condition out for the forces in both the horizontal and vertical directions, respectively, as: fcosî¸â’îľsn=0 fsinî¸+nâ’mg=0 in order to find the magnitude of force f, we have to solve a system of two equations with both f and the normal force n unknown. use the methods we have learned to find an expression for f in terms of m, g, î¸, and îľs (no n).

An object of dimensions 50 cm x 40 cm x 0.20 cm has a mass 60g. find its density in g/cm3 and kg/ m3

Imagine that someone pushes one marble toward a motionless marble. would there still be action-reaction forces involved in the collision? how might the marbles’ motions be changed? ?