Aperson lifts a 6.50kg box off the ground a vertical distance of 1.25m and then carries it horizontally across the room by 4.75m. 1). what is the work done by the person on the box? 2). what is the work done by gravity on the box? 3). what is the potential energy of the box as the person walks horizontally?

Astone is dropped from the upper observation deck of a tower, 250 m above the ground. (assume g = 9.8 m/s2.) (a) find the distance (in meters) of the stone above ground level at time t. h(t) = (b) how long does it take the stone to reach the ground? (round your answer to two decimal places.) s (c) with what velocity does it strike the ground? (round your answer to one decimal place.) m/s (d) if the stone is thrown downward with a speed of 2 m/s, how long does it take to reach the ground? (round your answer to two decimal places.) s