A train is moving with a speed of 50 miles per hour. A man standing in the rear of a train car throws a ball toward the front of the train with a speed of 10 miles per hour. If a stationary observer outside the train sees this happen, what speed is the ball moving with? Explain your answer.
50 miles per hour +10 miles per hour = 60 miles per hour!
To find the speed of the ball as observed by a stationary observer outside the train, we need to consider the concept of relative motion. The speed of an object is always measured with respect to the frame of reference from which it is being observed.
In this case, the train is already moving with a speed of 50 miles per hour. When the man throws the ball with a speed of 10 miles per hour, the ball inherits the train's initial velocity. The ball is not just moving forward with a speed of 10 miles per hour; it is also carried forward by the train's velocity of 50 miles per hour.
To calculate the net speed of the ball from the observer's perspective, we need to consider the vector sum of the train's velocity and the ball's velocity. Both velocities are in the same direction (toward the front of the train), so we simply add them together:
Net speed of the ball = Speed of the train + Speed of the ball
Net speed of the ball = 50 miles per hour + 10 miles per hour
Therefore, the net speed of the ball as observed by a stationary observer outside the train is 60 miles per hour.