I NEED HELP ASAP A marble at rest is dropped from a tall building. The marble hits the ground with a velocity of 98 m/s. How long was the marble in the air? (Remember: The acceleration due to gravity on Earth is 9.8 m/s2)
O 10 seconds
O 960.45
O 1.05
O 0.1 second​

Alidded glass container is filled with a colored gas. after a period of time, it is observed that the gas is uniformly spread throughout the box and that the movement has slowed considerably. next, a warm iron plate is carefully placed under the box. why is there resumed movement of the gas in the container?