Question

review - answer the questions.
a coach records distance and time measurements for a student during three different trials. the data are shown in the table below.
what is the students speed in trial 1?
what is the students speed in trial 2?
what is the students speed in trial 3?
what is the students average speed during the three trials?

Explanation:

Step1: Recall the speed formula

Speed \(v=\frac{d}{t}\), where \(d\) is distance and \(t\) is time.

Step2: Calculate speed for Trial 1

For Trial 1, \(d = 100m\) and \(t=13s\). So \(v_1=\frac{100}{13}\approx7.69m/s\).

Step3: Calculate speed for Trial 2

For Trial 2, \(d = 200m\) and \(t = 25s\). So \(v_2=\frac{200}{25}=8m/s\).

Step4: Calculate speed for Trial 3

For Trial 3, \(d = 400m\) and \(t = 56s\). So \(v_3=\frac{400}{56}\approx7.14m/s\).

Step5: Calculate average speed

Average speed \(v_{avg}=\frac{d_{total}}{t_{total}}\). \(d_{total}=100 + 200+400=700m\), \(t_{total}=13 + 25+56=94s\). So \(v_{avg}=\frac{700}{94}\approx7.45m/s\).

Answer:

Trial 1 speed: \(\approx7.69m/s\); Trial 2 speed: \(8m/s\); Trial 3 speed: \(\approx7.14m/s\); Average speed: \(\approx7.45m/s\)