What causes dust particles and tiny grains of soot to move with Brownian motion?

a. Flowing currents
b. Collisions with transparent microorganisms
c. The element fire
d. Collisions with invisible molecules

Using software, a simulation of a javelin being thrown both on earth and on the moon is created. in both cases, the velocity and angle of projection are kept the same. on earth, the javelin covers a distance y. what distance would it cover on the moon? (the moon’s gravity is about 1/6th that of earth.) a. 6y b. 6/y c. y/6 d. (y+6)2

Samir watches a 100-minute movie on his spaceship. maria's spaceshipe flies in the same direction as samir's spaceship but she observes his move to last 125 minutes and his spaceship to be 40 m long. how long does samir observe his own spaceship to be? according to an observer on earth, planet x is stationary. maria and samir depart earth on their spaceships at the same time, each flying at 0.5c. maria flies toward planet x and samir flies in the opposite direction. according to maria, her voyage to planet x takes 9 years. how many years does marias voyage take according to samir?

You've already seen the value of 9.8 in this lesson. what's this value called? what quantity does it represent?