Question

The value of 3.00 km in yards upto correct significant figures and scientific notation is, (1m = 1.094 yards)
(A) 3.282
(B) $3.28 \times 10^2$
(C) $3.28 \times 10^3$
(D) none of these

Answer 1

Hint: We are already given the relation between meter and yards in the question itself. We know that one kilometre is equivalent to a thousand metres. We make the conversion from kilometre to metre first and then we make the conversion of obtained metre to yards.

Complete answer:
First we convert the kilometres into metres so, 3 km is equivalent to:
$3 \times 1000 = 3000 $ m.
Now, we convert all the metres obtained into yards. Therefore, 1 yard is related to metres as:
$3000 \times 1.094 = 3.282 \times 10^{3}$ yards.

Therefore, the correct answer is option (C).

Additional Information:
The different units of distance mentioned here are used at different places. The ‘kilometre’ is commonly used in the standard notation. It is a commonly used unit in daily life like we use in general conversation as to how many kilometre distance is to be travelled. Metre is a smaller unit compared to kilometre and falls in the category of S.I. units. A yard is an imperial unit of distance and is used only for specific quantities like to describe the length of a pitch on the cricket ground. Yard is basically an English unit of length that also describes the length of a men’s belt in times like the 12$^{th}$ century.

Note:
Significant figures give a complete description of the digits present here. The rounding off is done according to some rules like if the last number is bigger than 5, we make an increment of 1 in the second last number. Although, here we have written all the three significant figures as they were only we have shifted the decimal.