Aliza needs to run at a rate faster than 8.8 feet per second in order to exceed her fastest time in a race. after running for 15 minutes, her coach determines that she is running at an average rate of 5.8 miles per hour. he converts the average rate to feet per second as shown below: he concludes that she is not running fast enough to exceed her fastest time. what errors did the coach make?

she needs to beat 8.8 ft /sec which is 0.001667miles/sec and after 15mins,she ran 0.00161miles/sec.

Step-by-step explanation:

1ft = 0.0001893939 miles

8.8ft= 0.001667

That means she needs to beat 0.001667 miles/sec time.

In 15mins, her average was 5.8miles/hr.

That means for 15mins,she ran 0.00161/sec.

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."