How long in hours would it take a runner to finish an 11 km race if she is running at a pace of 5.7 mi/hr?

It would take 1.16 h for the runner to finish the race .

Step 1. Convert kilometres to miles.

11 km × (0.621 mi/1 km) = 6.83 mi

Step 2. Calculate the time.

Time = 6.83 mi × (1 h/5.7 mi) = 1.16 h

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

i believe it is-

d.) gravity pulled particles of dust and gas together to form planets.