Aspacecraft with a proper length of 250 m passes by an observer on the earth. according to this observer, it takes 0.770 µs for the spacecraft to pass a fixed point. determine the speed of the spacecraft as measured by the earth-based observer.

Newton's law of universal gravitation states that the force f between two masses, m1 and m2, is given below, where g is a constant and d is the distance between the masses. find an equation that gives an instantaneous rate of change of f with respect to d. (assume m1 and m2 represent moving points.)

Jackson is designing a new heater, and he wants to experiment with different thermally conductive materials. which of these materials would be useful in conducting heat?

When the force acting on an object points at least partially in the direction of the motion the work done is considered to be negative