Consider two massless springs connected in parallel. springs 1 and 2 have spring constants k1 and k2 and are connected via a thin, vertical rod. a constant force of magnitude f is being exerted on the rod. the rod remains perpendicular to the direction of the applied force so that the springs are extended by the same amount. find the effective spring constant k of the two-spring system. give your answer for the effective spring constant in terms of k1 and k2.

The softest and hardest minerals are: softest hardest

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.

What are the north and south poles of a solenoid change with?