Instantaneous Velocity graph problem

In summary, to find the instantaneous velocity at 1 s, you need to know something about the object's motion at that point. This can be determined by taking the derivative of the position function or estimating the slope of the tangent line on a position vs. time graph. Simply knowing the position at 1 s is not enough information.
  • #1
iiskenny
2
0
Find the instantaneous velocity at 1 s.
Answer in units of m/s.

the coordinate for 1s is (1,4)

How do i find the instantaneous velocity?
 
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  • #2
welcome to pf!

hi iiskenny! welcome to pf! :smile:
iiskenny said:
Find the instantaneous velocity at 1 s.
Answer in units of m/s.

the coordinate for 1s is (1,4)

How do i find the instantaneous velocity?

by differentiating, or by drawing a tangent to the graph …

but what's the rest of this function? :confused:
 
  • #3
Velocity is defined as the rate of change of position divided by the rate of change of time.

This is the same as saying that velocity is the slope of the position vs. time graph.

Therefore, instantaneous velocity at 1s is the slope of the position vs. time graph at t=1s.
 
  • #4
But, as both tiny-tim and Beaker87 have said, just knowing the position is not enough! That's like saying "at 2:00, a car was at 4th st and Central ave. How fast was it going?"!

You need to know something about it motion through that point. An actual "position function", telling where it was at different times, would be excellent- take the derivative of the function. If you are given a "x versus t" graph, you can estimate the slope of the tangent line at the given point. If you are given a position at another time, before or after this t= 1 you can estimate the speed at t= 1. If you are given the position at times before and after as well as at t= 1, you can get a better estimate.

Now, what information are you really given? What is the full statement of the question?
 
  • #5


To find the instantaneous velocity at 1 s, you will need to calculate the slope of the tangent line at that point on the graph. This can be done using the formula for slope, which is change in y over change in x. In this case, the change in y would be the change in position, which is given by the y-coordinate (4). The change in x would be the change in time, which is given by the x-coordinate (1). So, the instantaneous velocity at 1 s would be 4/1 = 4 m/s. This means that at that specific moment in time, the object's velocity was 4 m/s.
 

What is "Instantaneous Velocity"?

"Instantaneous Velocity" is the velocity of an object at a specific moment in time. It is the rate of change of an object's position at a particular time.

How is "Instantaneous Velocity" different from "Average Velocity"?

"Average Velocity" is the total displacement of an object over a given time period, while "Instantaneous Velocity" is the velocity at a specific point in time. Average velocity is calculated by dividing the total displacement by the total time, while instantaneous velocity is calculated using calculus by finding the slope of the tangent line to the position-time graph at a specific point.

What is the significance of the slope of an "Instantaneous Velocity" graph?

The slope of an "Instantaneous Velocity" graph represents the acceleration of an object at a specific point in time. A positive slope indicates a positive acceleration, a negative slope indicates a negative acceleration, and a horizontal line indicates a constant velocity, with no acceleration.

How can "Instantaneous Velocity" be determined from a position-time graph?

The instantaneous velocity at a specific point on a position-time graph can be determined by finding the slope of the tangent line at that point. This can be done using the formula for slope, which is change in y over change in x, or by using calculus to find the derivative of the position function.

What are some real-world applications of "Instantaneous Velocity" graph problems?

"Instantaneous Velocity" graph problems are commonly used in physics and engineering to analyze the motion of objects. They can be used to calculate the acceleration of moving vehicles, the speed of projectiles, and the motion of particles in chemical reactions. These graphs can also be used to predict and model the behavior of complex systems, such as weather patterns or stock market trends.

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