Question

For whatever reason you have agreed to go on a trip with someone you don't especially like, furthermore, they have chosen the train, to get there, as a method of transportation. Slightly embittered, when they do not arrive on time you do not wait for them and board. You are grateful to be out of the pouring rain, and with great relief you find yourself alone in the train car as it disembarks. It is dark and cold outside, and unbeknownst to you, your friend has only just arrived to the platform in time to see you through the train window seated in a dry, warm cabin. The train reaches a speed of 10 m/s to pull away from the station. You friend's day gets even worse when they see clearly, through the window, that you pop the cork on a bottle of sparkling white grape juice in celebration, surrounded by smiling faces in the dining car. The cork ejects forward at 25 m/s. HOW FAST DOES YOUR FRIEND PERCEIVE THE CORK TO BE MOVING? (Galileo/Newtonian relativity)

Inside the same dining car as the preceding question, new friends celebrate the start of a shared voyage. It is soon decided that sparkling white grape juice to commemorate the moment is definitely in order, and the train attendant faithfully makes haste to fetch the proper vintage. Unaware of the misfortunes of the world, the bottle is uncorked, and the cork is ejected at 25 m/s forward. If the train is continuing to chug along out of the station at 10 m/s. HOW FAST DOES THE PARTY ON THE TRAIN PERCEIVE THE CORK TO BE MOVING?

You and your friend from the train story are said to be in __________________________ .

A. Thermal Contact

B. non-inertial reference frames

C.Mechanical Contact

D. relative motion

Answer 1

1) YOUR FRIEND PERCEIVE THE CORK TO BE MOVING at speed of 25+10 = 35 m/s as the friend is observing from outside the train, so according to the Newtonian relativity, the velocity will be observed as 35 m/s

2) THE PARTY ON THE TRAIN PERCEIVE THE CORK TO BE MOVING at a speed of 25 m/s only because there is zero relative motion between the other fellow being in the train and all are sitting at rest with respect to each other .

3) you and your friend from the train story are in RELATIVE MOTION .