a ball is thrown downward with an initial speed of 7 m/s. the ball's velocity after 3 seconds is m/s (g= -9.8m/s^{2}

Suppose you use a machine that gives you a mechanical advantage of 2 to achieve an output force of 30newtons what must the input force be

Acertain radio station broadcasts radio waves that have a wavelength of 298cm what is its broadcast frequency?

Determine the force the sun exerts on an object with a mass of 80.0 kg if that object is on the earth. what is the force exerted by the moon on the same object? what is the force the earth exerts on it?