A2.8-kg physics cart is moving forward with a speed of 45 cm/s. a 1.9-kg brick is dropped from rest and lands on the cart. the cart and brick move together across the horizontal surface. assume an isolated system. what equation do i use to figure out the the final valocity

Aball thrown by ginger is moving upward through the air. diagram a shows a box with a downward arrow. diagram b shows a box with an upward arrow. diagram c shows a box with a downward and upward arrow equal in size. diagram d shows a box with a downward and upward arrow with the downward arrow larger in size. which force diagram represents the forces on the ball? you may neglect the effects of air resistance.