The force f newtons between two magnetic poles is given by the formula f=1/(500r^2), where rm is their distance apart. find the rate of change of the force when the two poles are 0.2m apart and the distance between them is increasing at a rate of 0.03ms^-1

If you mix chlorine lithium in nickel together which two elements would be the most reactive

What are two different ways you could find the value of a? explain these methods.

Astudent throws a water balloon with speed v0 from a height h = 1.76 m at an angle θ = 21° above the horizontal toward a target on the ground. the target is located a horizontal distance d = 9.5 m from the student’s feet. assume that the balloon moves without air resistance. use a cartesian coordinate system with the origin at the balloon's initial position. (a) what is the position vector, rtarge t, that originates from the balloon's original position and terminates at the target? put this in terms of h and d, and represent it as a vector using i and j. (b) in terms of the variables in the problem, determine the time, t, after the launch it takes the balloon to reach the target. your answer should not include h. (c) create an expression for the balloon's vertical position as a function of time, y(t), in terms of t, vo, g, and θ. (d) determine the magnitude of the balloon's initial velocity, v0, in meters per second, by eliminating t from the previous two expressions.