Your shopping cart is moving without friction with constant velocity down and aisle in the grocery store. You drop a large can of beef stew straight down into the cart.
A)The cart speeds up because its mass has increased
B)The cart remains exactly the same velocity, because only its mass has increased
C)The cart slows down because its momentum is distributed over a larger mass
D)The cart remains exactly the same velocity, beacuse velocity is conserved
E)The cart speeds up because its momentum has increased
Hint:
No force acts in the horizontal direction, the horizontal component of the momentum is constant.
(mass of cart)*v(before) = (mass of cart + can)*v(after)
v(after) = v(before)*(mass of cart)/(mass of cart + can)
(mass of cart)/(mass of cart + can) < 1.