The discussion revolves around a physics problem involving an elevator moving at a constant velocity and the motion of keys released from a height within the elevator. The problem requires calculating the velocity of the elevator and analyzing the height difference when the keys are released while the elevator is moving upwards and then downwards.
The discussion is ongoing with participants questioning the definitions and assumptions related to the problem. Some guidance has been offered regarding the relationship between the elevator's motion and the keys' trajectory, but no consensus has been reached on the specific calculations or interpretations.
There is a focus on the implications of the elevator's constant velocity and the timing of the keys' release. Participants are also considering how the time of the elevator's upward motion relates to the time the keys take to fall, with some uncertainty about the relevance of the 2-second duration mentioned in the problem.
Can you be a bit clearer? We are now discussing the trajectory of the keys. Of the five variables I listed, acceleration, time, displacement, initial velocity and final velocity you correctly posted that we know the first three: a, t, s. Which velocity do we know?mdavies23 said:v
We know both initial=finalharuspex said:Can you be a bit clearer? We are now discussing the trajectory of the keys. Of the five variables I listed, acceleration, time, displacement, initial velocity and final velocity you correctly posted that we know the first three: a, t, s. Which velocity do we know?
Explain more. What do you think the initial speed is? How do you deduce it is the same as the final?mdavies23 said:We know both initial=final
The initial speed is the same as the elevator and the final speed is also the speed of the elevatorharuspex said:Explain more. What do you think the initial speed is? How do you deduce it is the same as the final?
Yes.mdavies23 said:The initial speed is the same as the elevator
No. This is a common blunder. The equations are for constant acceleration. As soon as the keys touch the ground the acceleration is no longer constant, so the the equations don't apply. We can only apply them up to the instant before they hit the ground, and at that time they will have quite a different velocity from the elevator's.mdavies23 said:the final speed is also the speed of the elevator