In a physics lab experiment, a spring clamped to the table shoots a 18 {\rm \;g} ball horizontally. when the spring is compressed 21 {\rm \;cm} , the ball travels horizontally 4.9 {\rm \;m} and lands

In a physics lab experiment, a spring clamped to the table shoots a 18 {\rm \;g} ball horizontally. when the spring is compressed 21 {\rm \;cm} , the ball travels horizontally 4.9 {\rm \;m} and lands on the floor 1.6 {\rm \;m} below the point at which it left the spring.