If you hold a backpack in your hand, the force of gravity pulls it downward. What force keeps it from falling to the ground?

Is 9 correct? and can someone me with 10? it’s due tomorrow, you

Light waves can move through , but they travel fastest when they move through a(n) .

Which formula equation represents the burning of sulfur to produce sulfur dioxide? s(s) + o2(g) 4502(9) 2h2s(s) + 302(g) —> 2h20(0) + 2502(9) 4fes2+1102 —> 2fe2o3 + 8502 2802(g) + o2(9) v205 , 2503(9)