The plates of an air-filled parallel-plate capacitor with a plate area of 15.5 cm2 and a separation of 9.15 mm are charged to a 150-V potential difference. After the plates are disconnected from the source, a porcelain dielectric with κ = 6.5 is inserted between the plates of the capacitor.(a) What is the charge on the capacitor before and after the dielectric is inserted?Qi= CQf= C(b) What is the capacitance of the capacitor after the dielectric is inserted?F(c) What is the potential difference between the plates of the capacitor after the dielectric is inserted?V(d) What is the magnitude of the change in the energy stored in the capacitor after the dielectric is inserted?J

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).

Do you agree with scientist’s prediction about the warming of alaska and other polar regions?

What properties of a moving object are used in determining the object's energy of motion