A cat sitting on top a train travelling north to south at a speed of #"70mph"# observes snow falling vertically downwards. In what direction will it be snowing for a dog sitting next to the train tracks?
We were told in class that it was a relativity problem and should be solved accordingly (vector addition) but I honestly don't understand how I could do that because I (probably mistakenly) think the snow should be falling straight down for the dog i.e. it should be the same for his frame of refernece.
We were told in class that it was a relativity problem and should be solved accordingly (vector addition) but I honestly don't understand how I could do that because I (probably mistakenly) think the snow should be falling straight down for the dog i.e. it should be the same for his frame of refernece.
1 Answer
At an angle...
Explanation:
If the cat sees the snow falling down vertically, it means it has a horizontal movement with the same velocity and direction as the train.
As the train moves South at 70 mph, the snow will also move South at 70 mph.
The cat therefore, sitting on top of the train, doesn't notice the horizontal movement of the snow relative to the ground, as he is travelling with the same speed and in the same direction (the same "Vector") So he is missing out on the Horizontal Vector....
For the dog however, the snow IS moving horizontally, with 70 mph, same speed as the train.
So, to describe the movement of the snow the way the dog sees it falling, there will be a horizontal component (Vector) as well as a Vertical one.
The actual angle at which the dog sees the snow falling will depend on the velocity with which the snow falls down. (Considered constant here, no acceleration)
