A tennis ball rolls off a high balcony railing and falls to the sidewalk. Its sideways drift carries it away from the building. Track only its downward motion.
You have seen free fall: a dropped ball speeds up downward at 9.8 m/s², gaining 9.8 m/s of downward speed each second.
The ball leaves the railing. Its downward speed starts growing at once. One second into the flight, it has gained 9.8 m/s of downward speed.
That is exactly a dropped ball's record. The sideways drift changes nothing about the downward readings.
Downward, a projectile speeds up at 9.8 m/s², exactly like a dropped ball.
A baseball leaves a table edge moving horizontally. Which statement describes its downward motion?
So every projectile flight carries a familiar motion inside it: the straight-down free fall you have already worked with.
A coin slides off a high balcony railing and falls for 1.5 s. How much downward speed does it gain in flight? Air resistance is ignored.
Write down the values in the question:
time in flight = 1.5 s
rate of gain = 9.8 m/s² (free fall)
downward speed gained = ?
Write down the equation:
downward speed gained = 9.8 m/s² × time
Substitute in the values:
downward speed gained = 9.8 m/s² × 1.5 s
Simplify:
downward speed gained = 14.7 m/s
A ball is knocked horizontally off a cliff ledge and is in flight for 2.0 s. Enter the downward speed it gains, in m/s.
A dart is in flight toward a dartboard, air resistance ignored. Compare its downward acceleration with a dropped dart's.
Which statement about a projectile's vertical motion is true?
A ball rolls off the flat roof of a tall building and is in flight for 3.0 s. Enter the downward speed it gains, in m/s.
A marble leaves a shelf moving horizontally. Which motion matches the marble's vertical motion exactly?