You are travelling in a bus. You are facing the direction in which the bus is moving. There is a video camera inside the bus. The camera is tied very tightly to a wall on the bus. It is so tightly tied that there is no relative movement between the camera and the bus. The camera is focussed on you. Initially the bus is stationary. You are sitting quietly and the camera is recording you. Suddenly the driver starts the bus. The camera continues to record you.

Once you reach your destination, then you check the recording of the camera. You find that when the driver started the bus, then the camera recorded you falling back.





Why did camera make such a recording?

perhaps due to newton's law of motion. Initially bus and the person were stationary with respect to ground. When suddenly bus moves forward, upper part of the person remain stationary in space, whereas camera started moving with bus, may this is the reason that camera show that ur falling back,,,, as you remain stationary for a while when bus started moving

obviosuly when bus started due to jerk you get back

greatttttttttttttt............. need lit more explain

tori explain dear

Suppose person was at position A and camera was at position B and distance between them is d. As the bus started moving, camera started moving as well whereas upper part of the person remained staionary for a time t, during this time bus moved a distance x, so the camera lower part of the person also travelled a distance x, whereas the upper part of the person travelled 0 distance. So camera will record same distance d for the lower part of the person whereas a distance d+x for the upper part of the person, after time t, his body will be stabilized and distance will become again d between camera and his upper part, so during recording, this differnce of distance and then covering this distance will show that he was falling at the start of bus

hahahah MJB nay to pora nomericla bana dia ok mein chota sa answer dete hoon easy sa....when bus starts camera and bus huamray liay stationary rehin gey but surronding kay liay nahi due to relative motion

ahn very nice u r right ,,The reason I posted this question is because often people say that the bus moves and they use inertia to explain why the passenger should fall backward. But, in camera's frame of reference, the bus never moves.

Your explanation is correct. You have used two frames of reference (ground and camera). There is another explanation, which requires the frame of reference to be put only on the camera.
Camera is tied to the bus. So, camera's frame is the same as the bus's frame. When driver starts the bus, then tyres rotate. Tyres push ground in the backward direction. By Newton's 3rd law, ground pushes tyres and thus the bus in the forward direction. This is force of friction. Bus moves because of this force of friction. Since there is a net external force on the bus, the bus's frame of reference is non-inertial and hence camera's frame is also non-inertial. The acceleration of this frame is in the forward direction.
When we study a system in non-inertial frame, then together with real forces, we should also consider pseudo force. The pseudo force is in the opposite direction of the direction of the frame's acceleration.
In our problem, system is passenger, frame of reference is on the camera (or we can also say, on the bus), frame's acceleration is in the forward direction. So, the pseudo force on the passenger is in the backward direction. Because of this pseudo force, the passenger falls backward.
The pseudo force acts on the lower portion of the passenger's body also. But this part does not move because when it tries to move, then the friction between the seat and the passenger body prevents the lower part of the body to move. If the seat is very smooth, then even the lower part will move somewhat.

thanks,,,,,,,,, waisey inni garhi physics ki taraf main ne ghor nahin kiya tha
afterall yahan relax kerney ko atey hain,,,,, scientific problem solve kerney ko nahin

wo tu theak hai relax kerney ko atey hain for entertainment per iss d=side ka kia matlab hai ( Riddle)
then

kuch tu pata chalna chay na

mind toara use hota hai werna tu mara always on rent