A ball is thrown horizontally, its initial speed is 10 m/s. It hits the gound after 4 seconds. How far away did it travel from its starting point?
The ball is thrown horizontally with an initial speed of 10 m/s and it hits the ground after 4 seconds. When the ball is released it moves in the downward direction due to the gravitational acceleration of 9.8 m/s^2. The distance moved by the ball in 4 seconds is 0*4 + (1/2)*9.8*16 = 78.4 meters.
In the same duration of time the ball also moves in the horizontal direction. There is no change in the horizontal speed as acceleration in this direction is zero. The distance moved by the ball is the product of its is initial velocity and the total time it travels for. This is equal to 10*4 = 40 meters.
The ball travels 40 meters in the horizontal direction and 78.4 meters in the vertical direction from the starting point.