- #1
graphicer89
- 55
- 0
A question about special relativity? Car reference vs Earth reference??
Hi I am prepping for a upcoming exam and I am trying to understand some concepts of physics and special relativity...which my exam will be on and i need to understand these problems so that i can know how to do the rest being that i was left in the dark without anything to guide my self by and i looked up information but i just don't understand it...and if you could help me out i would really appreciate it alot...I gave my 2 cents...which i hope can clear any doubts that i have...thanks again...
Lets say there are 2 pictures of someone flipping a coin and letting it drop in a car moving at a constant speed of 30 km/h. One picture is from the reference frame of the car and the other is from the reference frame of the earth.The path followed by the dropped coin is different in each frame of reference.
A) What force is acting on the dropped coin in the 2 frames of reference?
My guess that Gravity is the force that acts on both cause ..both are still on earth(obvious?)
B) Is the acceleration expererienced by the dropped coin the same in both frames of reference?If not how does it differ?
I think that in both cases it is the same speed because though the references are different they both in up in the same spot...just like a rock...if you throw a rock down it falls and it takes time...throw a rock and it falls but takes the same amount of time...
C) Is the initial speed of the coin the same in both frames of reference? (That is,is the initial speed of the coin compared to the car the same as the initial speed of the coin compared to objects outside the car?) If not how does it differ?
I think the initial speed of both coins are different mostly because of Earth's speed ...(thats where I am confused ...earth moves 30 km/h right? so wouldn't both initial speeds be the same??)...
D) According to Newton's Law, what path should the dropped coin follow in the frame of the reference of the car?
According to Newtons law ,the path of the coin should move in a straight line ...
E) According to Newtons's Law what path should the dropped coin follow in the frame of reference of the earth?
F) Does the example of the 2 references support or contradict the first postulate of special relativity? Why or Why not?
Yes because according to the first postulate we can't conduct an experiment that tells us where our frame of reference or another frame of reference is at rest or moving at constant velocity...(my gut isn't agreeing with me)
G) If you were inside the car, from the motion of the coin could you tell if you were at rest or moving at a constant speed relative to the ground?
I think i could tell that I am moving at a constant speed relative to the ground..(obvious?)
H) If you were standing as an observer outside the car, from the motion of the coin could you tell which was at rest, you or the car?
My guess is that i am at rest being that the coin travels faster as I am observer...
Hi I am prepping for a upcoming exam and I am trying to understand some concepts of physics and special relativity...which my exam will be on and i need to understand these problems so that i can know how to do the rest being that i was left in the dark without anything to guide my self by and i looked up information but i just don't understand it...and if you could help me out i would really appreciate it alot...I gave my 2 cents...which i hope can clear any doubts that i have...thanks again...
Lets say there are 2 pictures of someone flipping a coin and letting it drop in a car moving at a constant speed of 30 km/h. One picture is from the reference frame of the car and the other is from the reference frame of the earth.The path followed by the dropped coin is different in each frame of reference.
A) What force is acting on the dropped coin in the 2 frames of reference?
My guess that Gravity is the force that acts on both cause ..both are still on earth(obvious?)
B) Is the acceleration expererienced by the dropped coin the same in both frames of reference?If not how does it differ?
I think that in both cases it is the same speed because though the references are different they both in up in the same spot...just like a rock...if you throw a rock down it falls and it takes time...throw a rock and it falls but takes the same amount of time...
C) Is the initial speed of the coin the same in both frames of reference? (That is,is the initial speed of the coin compared to the car the same as the initial speed of the coin compared to objects outside the car?) If not how does it differ?
I think the initial speed of both coins are different mostly because of Earth's speed ...(thats where I am confused ...earth moves 30 km/h right? so wouldn't both initial speeds be the same??)...
D) According to Newton's Law, what path should the dropped coin follow in the frame of the reference of the car?
According to Newtons law ,the path of the coin should move in a straight line ...
E) According to Newtons's Law what path should the dropped coin follow in the frame of reference of the earth?
F) Does the example of the 2 references support or contradict the first postulate of special relativity? Why or Why not?
Yes because according to the first postulate we can't conduct an experiment that tells us where our frame of reference or another frame of reference is at rest or moving at constant velocity...(my gut isn't agreeing with me)
G) If you were inside the car, from the motion of the coin could you tell if you were at rest or moving at a constant speed relative to the ground?
I think i could tell that I am moving at a constant speed relative to the ground..(obvious?)
H) If you were standing as an observer outside the car, from the motion of the coin could you tell which was at rest, you or the car?
My guess is that i am at rest being that the coin travels faster as I am observer...
Last edited: