Topic: The height s above the ground at time t of an object is given by s(t) = -5t2 + vot + so where s is in meters, t is in seconds, v0 is the object's initial velocity in meters per second and s0 is its initial position in meters. a) If you throw a ball straight up from the ground with an initial velocity of 20 meters per second, how long will it take for the ball to hit the ground? Explain your reasoning. b) If you now throw the ball from the top of a tower which is 80 meters above ground, at the same initial velocity as in part a), when does it hit the ground? Explain your reasoning.

Because the sun is the biggest and if the sun orbits the earth we will be dead probably

W= fd
where f is an applied force and d is the distance over which it is applied. when a parachuting skydiver is at constant velocity, he is experiencing "terminal velocity", the point at which his acceleration down is canceled out by air resistance. that means that the resisting force of the air is equal to his weight, but in the opposite direction. with this, we can solve for the work done by the force.
w = fd
w = (92.0)(9.81 m/s^2) (325)
w= 2.93 x 10^5 j
the value for work in this case is positive because it is pushing up on the skydiver, who has a downward force of gravity.
therefore the answer is 2.93 x 10^5 j