If you run 12 km at an average speed of 4 km/h, how
much time does it take?

How many molecules are present in 3 mols of silicon dioxide (sio2)?

Drag each item into the proper state of matter category.

Ahanging spring stretches by 35.0 cm when an object of mass 450 g is hung on it at rest. in this situation, we define its position as x = 0. the object is pulled down an additional 18.0 cm and released from rest to oscillate without friction. what is its position x at a moment 84.4 s later? express your answer in cm.