According to john dalton’s observations when elements combine in a compound a. the ratio of their masses is always the same b. each element contributes an equal number of atoms c. there volumes are always equal d. their masses are always equal

Suppose a soccer ball is kicked from the ground at an angle 20.0º above the horizontal at 8.00 m/s. the y-velocity is determined to be 2.74 m/s. how long will the ball be in the air? assume the ball lands at the same height at which it was kicked.