When a ball is thrown vertically it travels upwards while slowing down, then stops momentarily and then comes back down. If we take "up" to be positive, the acceleration of the ball is negative both on the way up and on the way down. By measuring the distance travelled and time we can deduce that the acceleration due to gravity has a constant value close to the surface of the Earth: \(g=-9.81\text{ m s}^{-2}\)One way to measure the acceleration...