Question

which graphs show an object changing speed? select all that apply

Explanation:

Step1: Recall speed - distance - time relation

Speed is the rate of change of distance with respect to time. On a distance - time graph, the slope of the graph represents the speed.

Step2: Analyze first graph

The first graph is a curve. A curve on a distance - time graph means the slope is changing. Since slope = speed, a changing slope implies a changing speed.

Step3: Analyze second graph

The second graph is a straight line. The slope of a straight line is constant. So, the speed is constant.

Step4: Analyze third graph

The third graph is a straight line. The slope of a straight line is constant. So, the speed is constant.

Step5: Analyze fourth graph

The fourth graph is a curve. A curve on a distance - time graph means the slope is changing. Since slope = speed, a changing slope implies a changing speed.

Answer:

The first and the fourth graphs.