Question

7 in this velocity vs. time graph, the person at point a: motion on a walk a has zero acceleration b has positive acceleration c has negative acceleration d not enough information to determine

Explanation:

Step1: Recall the relationship between velocity - time graph and acceleration

Acceleration \(a=\frac{\Delta v}{\Delta t}\), where \(\Delta v\) is the change in velocity and \(\Delta t\) is the change in time. On a velocity - time graph, the slope of the graph represents acceleration, \(m = a=\frac{v_{2}-v_{1}}{t_{2}-t_{1}}\)

Step2: Analyze the slope at point A

At point A, as time \(t\) increases, the velocity \(v\) is also increasing. The slope \(m=\frac{\Delta v}{\Delta t}> 0\) (since \(\Delta v=v_{2}-v_{1}>0\) when \(t_{2}>t_{1}\)). When the slope of the velocity - time graph is positive, the acceleration is positive.

Answer:

B. has positive acceleration