A new roller coaster is advertised as having a perfectly efficient (energy is conserved) first drop without the presence of an additional applied force. Upon riding this roller coaster, a group of students question whether the roller coaster is actually perfectly efficient and want to design an experiment to test this question. The students hypothesized that inclined surfaces approach perfect efficiency as the surface increases in steepness. Design an experiment to test the hypothesis stated by the students above. The student has equipment that is typically found in a high school science laboratory. Identify at least two variables that will need to be held constant in order to have valid and replicable results.

Which is the best for showing percentages of different types of cars sold(gas hybrid , electric , other ) in the united states ?

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).

Oxygen undergoes an isentropic expansion from 120 degree c and 280 kpa absolute to 140 kpa absolute. determine the final temperature of the oxygen and the amount of work per kg of o_2 produced in the process if it is adiabatic.