depends....
Kilometers (KM)
or
Meters (M)
or if it was a toy train than...
Centimeters (CM)
The Unit Used To Measure A Train Can Be Kilometer.
you would measure it with feet
educate
Meters
You can use a radar gun or a speed measuring app on a smartphone to measure the speed of the train while standing on the platform. These devices work by emitting signals that bounce off the train and calculate the speed based on the Doppler effect.
It depends on what you are measuring because there are two types of muscles. If you are maxing and do 1 rep, then you measure your muscles' explosive capacity. If you do several reps (>8) you train your endurance instead. There is a fine line between endurance and explosiveness, but generally you can say that if you train 1-6 reps, its more explosive training. If you train 12-20 or more than that you train endurance. Between 8-12 you train both.
Hz = cycles/second, of a periodic phenomenon. So it depends on what cyclic feature of the train it is that you're trying to measure.
If you can't measure it, you can't train it might be a good answer to this question.
Metre (for its length). Kilometres per hour (speed) Tonnes (Mass)
The following are some of the items that are appropriate: The number of engines The number of cars the engines are pulling The total tonnage being pulled The speed at which the train is moving The total length of the train Fuel consumption per mile of travel
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.
Any movement must be specified - and measured - in relation to something. If you are inside a closed train, you see the walls of the train, and can measure or estimate your movement compared to the train, or the train's movement compared to your own position. But - assuming you don't see the outside - you don't know how fast the Earth is moving backwards with respect to the train (or the train with respect to Earth).