Three non-zero forces, f1, f2 , and f3, are acting on an object. forces f1 and f3 have opposite direction, and both are perpendicular to f2. under which conditions, if any, will the object be in equilibrium?

a. the magnitudes of f1 and f3 must be equal, and must be one half the magnitude of f2.

b. the magnitudes of f1 and f3 must be equal, and must be one third the magnitude of f2.

c. the magnitudes of f1, f2, and f3 must be equal.

d. no equilibrium

What is a good example of instantaneous speed

Asilver dollar is dropped from the top of a building that is 1324 feet tall. use the position function below for free-falling objects. s(t) = −16t2 + v0t + s0 (a) determine the position and velocity functions for the coin. s(t) = v(t) = (b) determine the average velocity on the interval [1, 2]. ft/s (c) find the instantaneous velocities when t = 1 second and t = 2 seconds. v(1) = ft/s v(2) = ft/s (d) find the time required for the coin to reach the ground level. (round your answer to three decimal places.) t = s (e) find the velocity of the coin at impact. (round your answer to three decimal places.) ft/s

Estimate the kinetic energy of the neptune with respect to the sun as the sum of the terms, that due to its daily rotation about its axis, and that due to its yearly revolution about the sun. [assume the neptune is a uniform sphere with mass = 1.0×1026 kg , radius = 2.5×1010 m , rotation period 16.1 h , orbital period 6.01×104 d and is 4.6×109 km from the sun.]