Add 7.3×10^7+1.8×10^7

Question

. Which is the correct sum?(1 point)
Responses

9.1×107
9.1 times 10 superscript 7 baseline

9.1+107
9.1 plus 10 superscript 7 baseline

8.1×107
8.1 times 10 superscript 7 baseline

9.1×1014

Answer 1

To add \( 7.3 \times 10^7 \) and \( 1.8 \times 10^7 \), you can first combine the coefficients:

\[ (7.3 + 1.8) \times 10^7 = 9.1 \times 10^7 \]

Thus, the correct sum is:

9.1×10^7 (or 9.1 times 10 superscript 7 baseline)

Answer 2

The population of a city is given as 3.45×106
. A nearby city has a population of 1.3×105
. What is the sum of the populations of the two cities in scientific notation?(1 point)
Responses

4.75×105
4.75 times 10 superscript 5 baseline

4.75×1011
4.75 times 10 superscript 11 baseline

35.8+105
35.8 plus 10 superscript 5 baseline

3.58×106

Answer 3

To find the sum of the populations of the two cities, we need to express both numbers in scientific notation and then add them.

1. The population of the first city is \( 3.45 \times 10^6 \).
2. The population of the second city is \( 1.3 \times 10^5 \).

Since \( 10^6 \) is larger than \( 10^5 \), we can convert \( 1.3 \times 10^5 \) to the same power of ten:

\[ 1.3 \times 10^5 = 0.13 \times 10^6 \]

Now we can add the populations:

\[ 3.45 \times 10^6 + 0.13 \times 10^6 = (3.45 + 0.13) \times 10^6 = 3.58 \times 10^6 \]

Thus, the sum of the populations of the two cities in scientific notation is:

3.58×10^6 (or 3.58 times 10 superscript 6 baseline).

Answer 4

An empty dump truck weighs about 2.8×105
pounds. How much does it weigh if 15,300 pounds of trash is added? The answer should be in scientific notation.(1 point)
Responses

29,530 pounds
29,530 pounds

4.33×105
pounds
4.33 times 10 superscript 5 baseline pounds

2.953×105
pounds
2.953 times 10 superscript 5 baseline pounds

15,302.8 pounds
15,302.8 pounds

Answer 5

To find the total weight of the dump truck when 15,300 pounds of trash is added, we start with the truck's weight and add the weight of the trash.

1. The weight of the empty dump truck is \( 2.8 \times 10^5 \) pounds.
2. The weight of the trash is 15,300 pounds, which can be converted to scientific notation as follows:

\[ 15,300 = 1.53 \times 10^4 \]

Now we need to add these two weights together, but for this, we can express \( 2.8 \times 10^5 \) in a compatible form:

\[ 2.8 \times 10^5 = 280,000 \text{ pounds} \]

To add, we can express \( 15,300 \) in powers of ten that match \( 2.8 \times 10^5 \):

\[ 15,300 = 0.153 \times 10^5 \]

Now we can add the values:

\[ (2.8 + 0.153) \times 10^5 = 2.953 \times 10^5 \]

Thus, the total weight of the dump truck with the trash added, in scientific notation, is:

2.953×10^5 pounds (or 2.953 times 10 superscript 5 baseline pounds).

Answer 6

The half-life of uranium-235 is 700,000,000 years. The half-life of uranium-238 is 4.463×1011
years longer. What is the half-life of uranium-238? The answer should be in decimal form.(1 point)
Responses

447,000,000,000
447,000,000,000

516,300,000,000
516,300,000,000

4.4637×1011
4.4637 times 10 superscript 11 baseline

11,463,000,000
11,463,000,000

Answer 7

To find the half-life of uranium-238, we first note the half-life of uranium-235, which is given as \( 700,000,000 \) years. The problem states that the half-life of uranium-238 is \( 4.463 \times 10^{11} \) years longer than that of uranium-235.

First, we convert \( 4.463 \times 10^{11} \) years into decimal form:

\[ 4.463 \times 10^{11} = 446,300,000,000 \text{ years} \]

Now we add this to the half-life of uranium-235:

\[ 700,000,000 + 446,300,000,000 = 447,000,000,000 \]

So, the half-life of uranium-238 is:

447,000,000,000 years.