Which pair of numbers shows the second number is an estimation of the first? (1 point)
345: 400
275; 200
0.00345; 0.004
0.00345: 0.003
Convert 8.0724 × 10-12 centimeters to kilometers. Express the answer to the exact decimal place.
Note: 1 kilometer is equal to 100.000 centimeters.
(1 point)
O 80.724 × 10-18 kilometers
O 8.0724 × 10-14 kilometers
O 8.0724 × 10-17 kilometers
O 8.0724 × 10-7 kilometers
To convert from centimeters to kilometers, we divide by 100,000.
8.0724 × 10^(-12) centimeters divided by 100,000 equals 8.0724 × 10^(-12) / (1 × 10^5) kilometers.
Simplifying the expression, we subtract the exponents: 8.0724 × 10^(-12-5) = 8.0724 × 10^(-17).
Therefore, the answer is: 8.0724 × 10^(-17) kilometers.
Denali, which is about 20,000 ft. above sea level, is the highest mountain in the United States. Mt. Everest, the
highest mountain on earth, is about 9 x 103 ft. higher than Denali. About how high is Mt. Everest? The answer
should be in scientific notation. (1 point)
0 2 9 x 104 ft
O 2.9 x 103 ft.
O 1.1 x 103 ft
O 29.000 ft.
To find the height of Mt. Everest, we need to add the height of Denali (20,000 ft) to the additional height above Denali (9 x 10^3 ft).
Adding these two heights together: 20,000 ft + 9 x 10^3 ft = 20,000 ft + 9,000 ft = 29,000 ft.
Therefore, Mt. Everest is approximately 29,000 ft high, which is represented in scientific notation as:
2.9 x 10^4 ft.
There are about 6 × 1019
atoms in a grain of sand. A cubic foot of sand can hold about 4 × 10° grains of sand
of average size. Using those figures, how many atoms would you expect to find in a cubic foot of sand? Write
the answer in scientific notation. (1 point)
O 2.4 x 1028
O 2.4 x 1029
O 24 x 1029
O 24 x 1028
To find the number of atoms in a cubic foot of sand, we need to multiply the number of atoms in a grain of sand (6 x 10^19) by the number of grains of sand in a cubic foot (4 x 10^0).
Multiplying these two numbers together: 6 x 10^19 atoms * 4 x 10^0 grains.
When multiplying numbers in scientific notation, we add the exponents: (6 * 4) x 10^(19+0) = 24 x 10^19.
Therefore, you would expect to find approximately 24 x 10^19 atoms in a cubic foot of sand.