Question

1. what is the instantaneous speed at 20 s? 6 mi/hr 28 m/s 6 m/s 30 mi/hr

Explanation:

Step1: Analyze the graph (implied, since it's a speed - time or distance - time graph for instantaneous speed at 20s). Assuming the graph has a horizontal segment at 20s (constant speed), we check the units. The question is about speed at 20 seconds, so the unit should be in m/s (since time is in seconds).

Step2: Eliminate options with mi/hr (miles per hour) as the unit is inconsistent with time in seconds. So 6 mi/hr, 30 mi/hr are out. Then, 28 m/s is likely too high if the graph's segment at 20s is horizontal with a reasonable speed, and 6 m/s is consistent.

Answer:

6 m/s (from the orange option: 6 m/s)