According to moh's hardness scale, your fingernail would be rated as 2.5. juan and carol are trying to identify an unknown mineral. carol can scratch the mineral sample with her fingernail. juan and carol know the mineral must be one of these four choices. based on the scratch test, the mineral is

You have trained year for a marathon. in your first attempt to run a marathon, you decide that you want to complete this 26-mile race in 4-5 hours. a. what is the length of a marathon in kilometers (1mile= 1.6 kilometers). b. what would your average speed have to be to complete the race 4.5 hours? give your answer in kilometers per hour.