Two balloons, one with a charge of 4.0 x 10 coulombs and the other with a charge of 8.2 x 106 coulombs, are kept 2.0 meters apart. What is the electric force between the two balloons? (k = 9.0 x 10^9 newton-meter^2/ coulombs^2)
A. 4,0 x 10^-2 newtons
B. 5.2 x 10^-2 newtons
C. 7.3 x 10^-2newtons
D. 8.2 x10^-6newtons

If a rock is thrown upward on the planet mars with a velocity of 12 m/s, its height (in meters) after t seconds is given by h = 12t − 1.86t2. (a) find the velocity of the rock after two seconds. m/s (b) find the velocity of the rock when t = a. 12−3.72a m/s (c) when will the rock hit the surface? (round your answer to one decimal place.) t = s (d) with what velocity will the rock hit the surface? m/s

(1 point) match the differential equations and their vector valued function solutions. you may wish to multiply at least one solution out fully, to make sure that you know how to do it. you can get the other answers quickly by process of elimination and just multiply out one row element.

The space between two 15-in.-long concentric cylinders is filled with glycerin (viscosity = 8.5 × 10-3 lb·s/ft2). the inner cylinder has a radius of 1 in. and the gap width between cylinders is 0.1 in. determine (a) the torque and (b) the power required to rotate the inner cylinder at 180 rev/min. the outer cylinder is fixed. assume the velocity distribution in the gap to be linear.