What is the instantaneous speed at t=30 minutes on the given graph?

  • Thread starter Thread starter Zashmar
  • Start date Start date
  • Tags Tags
    Speed
Click For Summary

Homework Help Overview

The discussion revolves around determining the instantaneous speed from a distance-time graph at a specific time, t=30 minutes. Participants are exploring the concept of slope as it relates to instantaneous speed and are referencing limits in their understanding.

Discussion Character

  • Conceptual clarification, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants are discussing how to calculate the slope of the graph at the specified time, with some suggesting different interpretations of the slope and its corresponding speed. Questions about the units on the axes are also raised, indicating confusion about the graph's scale.

Discussion Status

The discussion is active, with multiple interpretations of the slope being explored. Some participants are attempting to clarify the calculation process, while others are questioning the units used in the graph. There is no explicit consensus on the correct instantaneous speed yet.

Contextual Notes

There is confusion regarding the units on the axes of the graph, with participants debating whether the x-axis represents hours or minutes, and the implications this has on the slope calculation.

Zashmar
Messages
48
Reaction score
0
Gday mates,

This is my question
I uploaded a picture of the graph.
Calculate the instantaneous speed when t=30 minutes, I have read something about limits but I don't understand and I am getting really frustrated. Please help ;)

PS answer says 45 KLM/hour
 

Attachments

  • uploadfromtaptalk1362283955449.jpg
    uploadfromtaptalk1362283955449.jpg
    55.2 KB · Views: 328
Physics news on Phys.org
The instantaneous speed is the slope of the distance-time curve at t = 30 min
 
That is what I thought... In that case the answer would be 75k/h
 
Zashmar said:
That is what I thought... In that case the answer would be 75k/h
No, it's 45kph. Pls explain exactly how you are calculating the slope.
 
By finding the gradient of the line the 30 mins corresponds to, it is rise 3 run 4. So gradient is equal to 3/4 or 75klm
 
Zashmar said:
By finding the gradient of the line the 30 mins corresponds to, it is rise 3 run 4. So gradient is equal to 3/4 or 75klm
What are the units of each step on the y axis; likewise on the x axis?
 
Y axes is kilometers x-axis is hours
 
Zashmar said:
Y axes is kilometers x-axis is hours
No, x-axis is minutes.
 
Yea whoops
 
  • #10
Zashmar said:
Y axes is kilometers x-axis is hours
If the grid lines were km and hours then your 3/4 should have produced 0.75 km/h.
In fact, they're 5km and 5min.
 

Similar threads

Calculate the speed of a point based on a graph
  • · Replies 40 ·
2
Replies
40
Views
4K
What is the Average Speed and Acceleration of a Car on a Straight Road?
  • · Replies 45 ·
2
Replies
45
Views
5K
How to find/graph instantaneous speed vs time
  • · Replies 7 ·
Replies
7
Views
11K
Position-time graph made with info from a velocity time graph
  • · Replies 2 ·
Replies
2
Views
3K
Instantaneous Acceleration from a Velocity-Time graph
  • · Replies 6 ·
Replies
6
Views
7K
What is the intersection point of two objects on a position vs time graph?
  • · Replies 10 ·
Replies
10
Views
3K
Instantaneous velocity, help me please
  • · Replies 3 ·
Replies
3
Views
3K
How Do You Calculate Instantaneous Speed from a Speed-Time Graph?
  • · Replies 2 ·
Replies
2
Views
2K
Temperature change in different containers
  • · Replies 4 ·
Replies
4
Views
3K
Finding the Magnetic Field (B_0) on a Graph [NMR]
  • · Replies 6 ·
Replies
6
Views
2K