Final answer:
To calculate the time of flight for a bullet that hits 1.9 cm below the aiming point, we can use the equation for vertical motion due to gravity. The time of flight is found to be 0.0622 seconds. Without the horizontal distance, the speed cannot be calculated, but if the muzzle velocity is known, that would be the speed as the bullet emerges from the rifle.
Step-by-step explanation:
To determine the bullet's time of flight and speed as it emerges from the rifle, when it hits the target 1.9 cm below the aiming point, we can use the principles of projectile motion.
Given that the bullet hits 1.9 cm (0.019 m) below the aiming point, we consider only the vertical motion because the rifle is aimed horizontally. The vertical displacement (y) is 0.019 m. We can use the equation of motion y = 0.5 * g * t^2, where g is the acceleration due to gravity (9.8 m/s^2). Solving for t (time) gives:
t = sqrt((2 * y) / g) = sqrt((2 * 0.019 m) / 9.8 m/s^2) = 0.0622 s.
This is the time of flight for the bullet. For the speed (v), we divide the horizontal distance (x) by the time of flight (t). If the horizontal distance is not given, we cannot calculate the speed without additional information. However, if the muzzle velocity is known, this would be the speed as it emerges from the rifle.
In problems similar to this, the horizontal motion and vertical motion are independent of each other. Therefore, the horizontal speed remains constant if air resistance is negligible.