In a standard lab, students drop blocks on moving carts. A cart with a mass of 3.4 kg is moving with a velocity of 23.9 m/s. A block with a mass of 2 kg is dropped onto the moving cart. What is the velocity of the cart after the block is dropped?
a
3.4 m/s
b
23.9 m/s
c
5.4 m/s
d
15.1 m/s