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Question
In figure shows the x coordinate of a particle as a function of time. Find the sings of vx and ax at t = t1, t = t2 and t = t3.
Solution
The slope of the x–t graph gives the velocity, and the change in the slope gives the acceleration.
At t = t1,
Slope = Positive ⇒ Velocity = Positive
The slope is increasing ⇒ Acceleration = Positive
At t = t2,
Slope = Constant ⇒ Velocity = Zero
The slope is constant ⇒ Acceleration = Negative
At t = t3,
Slope = Negative ⇒ Velocity = Negative
The slope is increasing ⇒ Acceleration = Positive
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