solar energy from the sun travels at the speed of 299,274 km/s. what is the scientific notation using three significant digits

Question

 i need help with my science problem and im already failing please help me!!!!!!

 

Answer 1

2.99x(10^5)

 

Note: 10^5 means 10 to the 5th power.

Answer 2

Scientific notation has two basic parts, the significant digits and the exponent.

 

299,274 is six digits, which is more that the 3 significant digits that you need.

 

You can either round first and then apply the exponent, or apply the exponent, then round.

 

Rounding first:

1) Round so that you keep the three digits to the far left of the number, making all the digits to the right 0's.

 

299,000

 

2) Apply the exponent

 

299,000 x 10^0  (10^0 = 1)

 

3) Move the decimal place so that it sits to the right of the digit on the far left

 

29,900.0 x 10^1

2,990.00 x 10^2

299.000 x 10^3

29.9000 x 10^4

2.99000 x 10^5

 

4) Drop all but the 3 significant digits

 

2.99 x 10^5

 

 

Exponent first:

 

1) Apply the exponent

299,274 x 10^0 (10^0 = 1)

 

 

3) Move the decimal place so that it sits to the right of the digit on the far left

29,927.4 x 10^1
2,992.74 x 10^2
299.274 x 10^3
29.9274 x 10^4
2.99274 x 10^5

3) Round so that you keep the three digits to the far left of the number, making all the digits to the right 0's.

2.99000 x 10^5

 

4) Drop all but the 3 significant digits

2.99 x 10^5



Hope this helps.

Answer 3

Three significant digits would be 299 since you round off.  If the next number was 5 or greater than it would be rounded up to 300.  The power of ten is computed by moving the decimal point to the place where the three significant digits are 2.99 and not 299.  In this case the decimal point (although not shown) is just to the right of the 4.  Or in reality the number could be written 299274.0   For every place that you mone the decimal point to the left the power of ten goes up by 1.

    29927.4 X 10

    2992.74 X 10^2

    299.274 X 10^3

    29.9274 X 10^4

    2.99274 X 10^5

 

Then using only the significant digits gets you 2.99 x 10^5.

 

Hope this helps.