What do scientists use observations for?

An object is dropped from a tower, 400 ft above the ground. the object's height above ground t seconds after the fall is s(t)equals400 minus 16 t squared. determine the velocity and acceleration of the object the moment it reaches the ground. the velocity of the object the moment it reaches the ground is nothing ft/s.

If a sphere and a cure have the same mass and are propelled up a ramp with the same force, which would travel father up the ramp? explain.

The least penetrating form of radiation is