Scarlett is analyzing a position-time graph of a moving train. Which quantity can be found by measuring the slope of a line that is tangent to a point on the graph?

acceleration
displacement
average velocity
instantaneous velocity

D. instantaneous velocity.

Explanation:

A position-time graph is a graph of the position of an object against (versus) time. The slope of the line of a position-time graph is typically used to determine or calculate the velocity of an object.  

In this scenario, Scarlett is analyzing a position-time graph of a moving train. The quantity which can be found by measuring the slope of a line that is tangent to a point on the graph is the instantaneous velocity.

An instantaneous velocity can be defined as the rate of change in position of an object in motion for a short-specified interval of time.

For example.

Given that the equation of motion is S(t) = 10t² + 5t + 20. Find the instantaneous velocity at t = 5 seconds.

Solution.

Differentiating the equation, we have;

Substituting the value of "t" into the equation, we have;

S(t) = 60m/s.

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i think the answer is a, hope this is right, that would be my best guess.