Just add or subtract (depending on the direction) the speed of the ball (in relation to the train) to the speed of the train (in relation to the ground).
The above assumes the speeds are not close to the speed of light; if they are, more complicated formulae are required.
The clock on train B would appear to be the same width and to run at the same rate
A person standing on the ground. For the person on the train, ground is moving and the train is stationary.
the person standing on the ground, the train is moving and the ground is stationary. but the person on the train looks he is stationary and the ground is moving.
It can be done by moving the sound source quickly towards the observer (or the observer towards the sound), like a siren on a speeding train, and is known as the Doppler effect.See related link.
In order to talk about a physical phenomenon, an observer describing it is needed. For example, if you look at a running can from a running train or still on the street border, the motion is quite different. For example, if the train and the car run in parallel on a street and a railway and the train is faster than the car, you see the car going on in a certain direction from the street border, and in the opposite direction from the train. The reference system is no more that the specification of the position and motion status of the observer. Laws of physics allows you to derive the description of a phenomenon in a certain system if you know it in another system, that means that an observer can calculate as the phenomenon is seen from another observer if he knows how the second observer moves. No physical phenomenon can be described if the reference system is not specified, even if sometimes the reference system specification is obvious so that it is not explicitly named. For example, the person describing a car run do not underline that it is described as looked from an observer that is still on the border of the circuit. However, the car run appears very different if observed from one of the involved cars :-)
Relative motion. To talk about a train moving at a certain speed usually means that the train is moving at a certain speed relative to a stationary observer (relative to the ground). This however also means that a passenger traveling in said train would experience the ground (and every other stationary object) as the moving object. This is why a stationary train may seem to be moving to passengers of an already moving train.
the answer is relative.. if you are standing on the same train, for you the man will be running as fast as it would do on the ground. If you are standing on the ground, then his speed relative to you will be the composition of the train speed + his speed. to make it more interesting.. think now that the train it's running with a speed that approach the speed of light relative to you.
The clock on train B would appear to be the same width and to run at the same rate
Yes that is the case.
If you've stood beside the tracks when a train is passing at speed, you might have felt the ground shake with the weight of the train. The faster it goes, the more the ground shakes. To save the bridge from being shook up that much, the train slows down.
To a person inside the train the fly is just flying around as flies ordinarily do. To an observer outside of the train the fly is moving at 90kmh relative to the ground, with slight variations due to its flying movement. To someone observing from space, you would have to account for the earth's movement as well. The fly's movement will depend on the reference frame of the observer.
A person standing on the ground. For the person on the train, ground is moving and the train is stationary.
High-speed train; 'Train Grande Vitesse' or, TGV for short
train a grande vitesse is the name of the french high speed train
Bob wants to obtain a life-size train.
Before you step off of the train, your body is moving past the walkway at the same speed as the train. Its natural tendency is to keep moving in the same direction at the same speed, but once you step onto the walkway, that means your body wants to move along the walkway at the speed of the train. You have to slow your body down gradually, which you can only do by deftly manipulating the contact between the walkway and your feet. If you stepped off and expected to just stand there, your feet might stay on the walkway, but the rest of you still needs to keep going at the speed of the train, resulting in a phenomenon known as "falling down".
The maximum speed reached by the TGV was set in a record for the fasted wheeled train as 357.2 mph. TGV stands for Train a Grande Vitesse, meaning high-speed train in french.