Simon is riding a bike at 12 km/h away from his friend keesha. he throws a ball at 5 km/h back to keesha, who is standing still on a sidewalk.  how fast would keesha say the ball is traveling toward her?

Ithink 2 is the correct

The density of water is 1 g/cm cubed and in order for the pebble to sink its density has to be greater than the density of water and in order for the twig to float its density has to be less than the density of water