For the following situations given the system described, which of the quantities listed should be zero? for those that are not zero, provide its sign. (external work, change in kinetic energy, change in gravitational potential energy, change in elastic potential energy, change in thermal energy)

Me ! a 2 µc charge q1 and a 2 µc charge q2 are 0.3 m from the x-axis. a 4 µc charge q3 is 0.4 m from the y-axis. the distances d13 and d23 are 0.5 m. find the magnitude and direction of the resulting vector r. round your answer to the nearest tenth.

Uranium has two naturally occurring isotopes. 238u has a natural abundance of 99.3% and 235u has an abundance of 0.7%. it is the rarer 235u that is needed for nuclear reactors. the isotopes are separated by forming uranium hexafluoride uf6, which is a gas, then allowing it to diffuse through a series of porous membranes. 235uf6 has a slightly larger rms speed than 238uf6 and diffuses slightly faster. many repetitions of this procedure gradually separate the two isotopes. what is the ratio of the rms speed of 235uf6 to that of 238uf6? express your answer to five significant figures.

Aleaky 10-kg bucket is lifted from the ground to a height of 15 m at a constant speed with a rope that weighs 0.7 kg/m. initially the bucket contains 45 kg of water, but the water leaks at a constant rate and finishes draining just as the bucket reaches the 15-m level. find the work done. (use 9.8 m/s2 for g.) show how to approximate the required work by a riemann sum. (let x be the height in meters above the ground. enter xi* as xi.) lim n → ∞ n (9.8)(45−3 xi) i = 1 δx express the work as an integral. 0 dx evaluate the integral. (round your answer to the nearest integer.) j