Need help understanding relative velocity problem

[Shindo]

Homework Statement

The escalator that leads down into a subway station has a length of 30.0 meters and a speed of 1.8 meters/second. relative to the ground. A student is coming out of the station by running in the wrong direction on this escalator. The local record time for this trick is 11 seconds. Relative to the escalator what speed must the student exceed in order to beat the record?

My question: I don't understand what this question is asking. What does it mean by "running the wrong direction on this escalator"? Any help on what this question is asking, and what I need to find is very appreciated.

 

[Redbelly98]

Homework Statement

The escalator that leads down into a subway station has a length of 30.0 meters and a speed of 1.8 meters/second. relative to the ground. A student is coming out of the station by running in the wrong direction on this escalator. The local record time for this trick is 11 seconds. Relative to the escalator what speed must the student exceed in order to beat the record?

My question: I don't understand what this question is asking. What does it mean by "running the wrong direction on this escalator"? Any help on what this question is asking, and what I need to find is very appreciated.

Welcome to PF.

The "wrong" direction means that the person is running on the escalator in the opposite direction that the escalator is moving. Normally, a person would either stand on the escalator and move in with the same speed and the same direction as the escalator, OR walk on the escalator in the same direction that the escalator is already moving.

 

[Shindo]

The "wrong" direction means that the person is running on the escalator in the opposite direction that the escalator is moving.

Okay, but just to clarify, the question is asking how fast the person needs to run a 30 meter distance, with 1.8 m/s of force AGAINST him; all that it is faster than 11 seconds?

 

[Redbelly98]

Yes.

(Except that 1.8 m/s is a speed, not a force. )

 

[Nickie]

The question is asking for the speed at which the student must run in order to beat the record time of 11 seconds for running in the opposite direction on the escalator. To find this speed, we need to consider the relative velocities of the student and the escalator.

The escalator is moving downwards at a speed of 1.8 meters/second relative to the ground. This means that the student, who is running in the opposite direction, must have a relative velocity that is greater than 1.8 meters/second in order to beat the record time.

To calculate the relative velocity of the student, we can use the formula v = v1 + v2, where v is the relative velocity, v1 is the velocity of the escalator, and v2 is the velocity of the student.

In this case, v1 = -1.8 meters/second (since the escalator is moving downwards) and v2 is what we need to find.

We also know that the escalator has a length of 30.0 meters and the record time is 11 seconds. This means that the student must cover a distance of 30.0 meters in 11 seconds in order to beat the record.

Using the formula d = vt, where d is the distance, v is the velocity, and t is the time, we can rearrange it to find v.

v = d/t = 30.0 meters/11 seconds = 2.73 meters/second

Therefore, the student must have a relative velocity of 2.73 meters/second in order to beat the record time of 11 seconds while running in the opposite direction on the escalator.