A ball is thrown straight upward, with air resistance too small to matter. While it rises, by how many m/s does its speed drop during each second of flight? Enter the number only.
A ball leaves your hand moving upward. Gravity does not pause while it rises: the free-fall acceleration acts from the moment the ball leaves your hand. That one fact predicts the velocity at every later second.
A ball leaves at 19.6 m/s upward. One second later: 19.6 − 9.8 = 9.8 m/s upward — still rising, but slower. One second after that: 0. Another second: 9.8 m/s downward. And another: 19.6 m/s downward.
Taking up as positive, the same list reads +19.6, +9.8, 0, −9.8, −19.6 m/s — one subtraction of 9.8 m/s for each second of flight.
A ball is hit straight up at 29.4 m/s. Air resistance is ignored. What is its velocity 2 s later?
Each second of flight shifts the velocity 9.8 m/s downward.
After 1 s: 29.4 − 9.8 = 19.6 m/s upward.
After 2 s: 19.6 − 9.8 = 9.8 m/s upward.
The velocity is 9.8 m/s upward.
A ball is launched straight up at 39.2 m/s. Air resistance is ignored. Taking up as positive, what is its velocity 3 s after launch? Enter the value in m/s, including its sign.
A stone is flung straight up at 24.5 m/s from the edge of a quarry, and on the way down it falls past the edge. Air resistance is ignored. What is its velocity 4 s after launch?
Four seconds of flight shift the velocity 4 × 9.8 = 39.2 m/s downward.
Taking up as positive: 24.5 − 39.2 = −14.7 m/s.
The velocity is 14.7 m/s downward.
A beanbag is tossed straight up at 14.7 m/s. Air resistance is ignored. Taking up as positive, what is its velocity 2 s after launch? Enter the value in m/s, including its sign.
A ball is fired straight up from a spring launcher at 34.3 m/s. Air resistance is ignored. Taking up as positive, what is its velocity 5 s after launch? Enter the value in m/s, including its sign.
A ball is served straight up at 49 m/s. Air resistance is ignored. Taking up as positive, what is its velocity 6 s after launch? Enter the value in m/s, including its sign.
A ball is thrown straight up at 24.5 m/s. Air resistance is ignored. How many seconds after launch is the ball moving at 4.9 m/s downward? Enter the time in seconds.
A test sphere is launched straight up at 44.1 m/s. Air resistance is ignored. Taking up as positive, what is its velocity 4 s after launch? Enter the value in m/s, including its sign.