The discussion revolves around calculating the total displacement of a passenger walking on a bus that is moving in a specific direction. The problem involves relative motion, specifically how the passenger's movement relates to the bus's velocity and direction.
The discussion is active, with participants providing insights and questioning each other's interpretations. There is no explicit consensus, but various lines of reasoning are being explored regarding the definitions of velocity and the implications of the problem statement.
Some participants note that the problem may lack sufficient information to calculate the displacement accurately, and there is an emphasis on the importance of providing a complete problem statement in homework submissions.
CWatters said:Is that the exact problem statement word for word? I ask because it's not possible to calculate the displacement without more information.
Meanwhile try working out how fast the passenger is traveling (with respect to the ground).
The question asks for the passesnger's velocity relative to the road, but I was unsure about how to find displacement because you need displacement to calculate velocity.CWatters said:Is that the exact problem statement word for word? I ask because it's not possible to calculate the displacement without more information.
Meanwhile try working out how fast the passenger is traveling (with respect to the ground).
No, you don't. Velocity is a vector quantity. Vector quantities can be added and subtracted vectorially.Balsam said:The question
The question asks for the passesnger's velocity relative to the road, but I was unsure about how to find displacement because you need displacement to calculate velocity.
SteamKing said:No, you don't. Velocity is a vector quantity. Vector quantities can be added and subtracted vectorially.
Read the problem statement carefully again. It doesn't give you just speed; a direction is also specified for the travel of the bus and the person walking in the aisle.Balsam said:So how would you calculate the velocity, because the question only gives you 2 speed values?
I thought velocity was the rate at which an object is displaced while speed is the rate at which an object changes position-- doesn't that mean that you can't add a direction to speed and turn it into a velocity value, because they're not the same? Ex. An object that takes two seconds to move from a starting position forwards 2m and back 2m has a speed of 2m/s, but it has a velocity of 0m/s because it's not being displaced- I don't know if that's true, but that's what I think.SteamKing said:Read the problem statement carefully again. It doesn't give you just speed; a direction is also specified for the travel of the bus and the person walking in the aisle.
Speed + Direction = Velocity.
Displacement is a change in position. It is a vector.Balsam said:I thought velocity was the rate at which an object is displaced while speed is the rate at which an object changes position-- doesn't that mean that you can't add a direction to speed and turn it into a velocity value, because they're not the same? Ex. An object that takes two seconds to move from a starting position forwards 2m and back 2m has a speed of 2m/s, but it has a velocity of 0m/s because it's not being displaced- I don't know if that's true, but that's what I think.
SteamKing said:Read the problem statement carefully again. It doesn't give you just speed; a direction is also specified for the travel of the bus and the person walking in the aisle.
Speed + Direction = Velocity.
Balsam said:I thought velocity was the rate at which an object is displaced while speed is the rate at which an object changes position-- doesn't that mean that you can't add a direction to speed and turn it into a velocity value, because they're not the same? Ex. An object that takes two seconds to move from a starting position forwards 2m and back 2m has a speed of 2m/s, but it has a velocity of 0m/s because it's not being displaced- I don't know if that's true, but that's what I think.
So wouldn't the person's velocity just be 3km/h[N]? If so, what was the point of the bus' speed being given?CWatters said:Thats not relevant to this problem.
Velocity has two components, speed and direction.
The problem statement contains all the info needed to work out both components on their own. No need to add the two components.
Some examples of velocity...
100mph heading North.
60 meters per second vertically upwards.
4kts heading west along the equator.
According to you, the problem asks for the passenger's velocity relative to the road. This is why Item No. 1 in the HW template asks posters to provide a complete problem statement.Balsam said:So wouldn't the person's velocity just be 3km/h[N]? If so, what was the point of the bus' speed being given?
Emphasis added.CWatters said:Thats not relevant to this problem.
Velocity has two components, speed and direction.
The problem statement contains all the info needed to work out both components on their own. No need to add the two components.
SteamKing said:Except, according to Post #3, the problem asks for the passenger's velocity relative to the road.
SteamKing said:Speed + Direction = Velocity.