At a soccer practice, the players run sprints. they start at the goal, run 10 m toward the center of the field and then run back to the goal. then they run 20 m toward the center of the field and back to the goal. finally they run 30 m toward the center of the field, turn around, and run back to the goal again. one player times herself to try and beat her personal best time. she runs the first 10 m in 2.5 s and gets back to the goal in 2.8 s. then she runs the 20-m sprint in 5.7 s and gets back to the goal in 6.7 s. she runs the final 30-m sprint in 12 s and gets back to the goal in 15 s. what was her average velocity for the entire exercise?

2.68 m/s

Explanation:

The total distances she runs in this exercise is:

First 10m sprint and back = 10 * 2 = 20m

2nd 20m sprint and back = 20 * 2 = 40m

The last 30m sprint and back = 30 * 2 = 60m

So the total distance = 20 + 40 + 60 = 120m

The total time she takes to run all these tracks:

2.5 + 2.8 + 5.7 + 6.7 + 12 + 15 = 44.7s

So here average speed for the entire exercise is

120 / 44.7 = 2.68 m/s

hello, i am papaguy.

i have found an answer to your question but use it as information.

information: because weak acids/bases have low concentration of hydrogen ions, the addition of water has a large impact on the ph. 2. a difference in 1 unit is a 10x difference in concentration for example; a liquid with ph of 3 is 10x more acidic than a liquid with a ph of 4. therefore, a liquid with a ph of 3 is stronger.

best of luck!

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west