Determine whether each activity has a mainly positive or mainly negative effect on the environment. burning fossil fuels, recycling glass and plastic, planting trees and shrubs, venting methane into air from landfills, fracking in unstable soil

Ahot-air balloon is drifting straight downward with a constant speed of 2.40 m/s. when the balloon is 7.63 m above the ground, the balloonist decides to drop one of the ballast sandbags to the ground below. how much time elapses before the sandbag hits the ground?

An isolated conducting spherical shell carries a positive charge. part a which statement (or statements) about the electric field and the electric potential inside and outside the spherical shell is correct? which statement (or statements) about the electric field and the electric potential inside and outside the spherical shell is correct? electric potential inside the shell is constant and outside the shell is changing as 1/r2 both the electric potential and the electric field does change with r inside and outside the spherical shell electric potential inside and outside the shell is constant, but not zero electric potential inside the shell is constant and outside the shell is equal to zero electric field inside and outside the shell is constant (does not change with the position r), but is not equal to zero electric field inside and outside the shell is changing as 1/r (where r is the distance from the center of the sphere) electric field inside is equal to zero and outside the shell is constant, but not zero electric potential inside the shell is constant and outside the shell is changing as 1/r electric field inside and outside the shell is changing as 1/r2 electric field inside is equal to zero and outside the shell is changing as 1/r2 electric field inside and outside the shell is zero electric field inside is constant and outside the shell is changing as 1/r

Aspectroscope breaks light up into its colors, allowing scientists to analyze light from the solar system and universe. by studying the spectral line patterns, widths, strengths and positions, scientists can determine the speed, position, and of celestial bodies. a) age b) origin c) rotation d) temperature