PHYSICS HELP! I'm stuck and would appreciate kind of help :)

What property of an object determines its inertia?

If an electric circuit is not grounded it is best to reach out and touch it to provide the ground a. true or b. false

An astronaut on the moon throws a baseball upward. the astronaut is 6 ft, 6 in. tall, and the initial velocity of the ball is 3030 ft per sec. the height s of the ball in feet is given by the equation s equals negative 2.7 t squared plus 30 t plus 6.5s=−2.7t2+30t+6.5, where t is the number of seconds after the ball was thrown. complete parts a and b.