Why is the use of existing data, especially in comparative and historical research, especially helpful to students?

For more Information and insight.

Step-by-step explanation:

The use of historical and comparative existing data is important to students because it gives them an insight on what they are working on.

Previous datas contains certain informations from which new observations and assessments can be made.

Students uses existing data to compare and contrast different factors like if there was a rise or fall in the system they are working on, the also check if an major changes occurred or things were significantly the same from the past to present.

54 kilometers per hour

step-by-step explanation:

according to rules:

1 km = 1000 meter

which means that 1 meter = 1/1000 km

1 hour = 3600 second [ as 1 hour = 60 min = 60 *60 seconds ]

which means that 1 second = 1/3600 hour

therefore, 1 kilometer/hour =

thus to convert 15 meter per second to kilometer per hour, we multiply 15 to 3.6 kilometer/hour.

15 meter/second=   which is the required answer.

answer:   b

step-by-step explanation:

x2 = 16

x can not be a negative number because 16 is positive

the only answer would be positive 8