Answer: Time taken by a sound impulse to travel through an aluminum rod 25 kilometers long is 4.9 seconds.
Solution:
Length of aluminium rod = 25 km = 25000 m (1 km=1000 m)
Time taken by sound to travel through aluminium = 5100 m/s (from the table given)
time taken =
Hence, the correct option is 4.9 seconds.
Answer : The correct answer is Option D.
Explanation:
Ores are defined as natural occurring substance from which metals and another mineral are extracted.
Bauxite is primary ore of an aluminium metal. it doesn't have definite or specific chemical composition. This is because it contains mixture of hydrous aluminum oxide, aluminum hydroxides
, insoluble materials like hematite, quartz ,geothite ,magnetite etc.
From the given options the most appropriate statement which is correct about the bauxite is 'It does not have a definite chemical composition'.
Hence, the correct option Is (D).