You are sharing a house with a few roommates. one of them plays on the basketball team, and is exactly 200 cm tall. the heights of you and the other roommates are 188 cm, 175 cm, and 160 cm. you want to buy the minimum height mirror that will allow all of you to see your entire selves, when the mirror is mounted in a fixed position on the wall. assume each person's eyes are at a level 95% of their height. how many centimeters above the floor should the top of the mirror be?

What is the difference between mass density and weight density?

Two point charges lie on the x axis. a charge of + 2.30 pc is at the origin, and a charge of − 4.50 pc is at x=−11.0cm. what third charge should be placed at x=+26cm so that the total electric field at x=+13.0cm is zero? express your answer to three significant figures and include appropriate units.

Wo 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).