Answer:
The graph is shown below.
The athlete's speed at the finish line is 11 m/s
Total distance covered is 82.5 m.
Explanation:
The graph of speed versus time is drawn below.
Acceleration in the first 5 seconds, [tex]a=2.2[/tex] m/s²
From the graph, the slope of line OA is the acceleration in the first 5 seconds.
Slope of line OA is given as:
[tex]slope, a=\frac{AD}{OD}\\2.2=\frac{AD}{5}\\AD =2.2\times 5=11\textrm{ m/s}[/tex]
Now, the length AD is nothing but speed at point A or B as AB is a straight line.
Therefore, the speed when crossing the finish line is the speed at B which is equal to 11 m/s.
Distance covered is given by the total area under the graph.
The total area can be divided into two shapes; a triangle and a rectangle.
The area under the graph is the sum of areas of triangle OAD and rectangle ABCD.
Area of triangle OAD is, [tex]A_{tri}=\frac{1}{2}\times OD\times AD=\frac{1}{2}\times 5\times 11=27.5[/tex]
Area of rectangle ABCD is, [tex]A_{rec}=AB\times AD=5\times 11=55[/tex]
Therefore, the total distance covered till the finish line is given as:
[tex]d_{total}=27.5+55=82.5\textrm{ m}[/tex]
