An empty dump truck weighs about 2.8×10^5 pounds. How much does it weigh if 15,300 pounds of trash is added? The answer should be in scientific notation.(1 point)

Answer 1

The weight of the dump truck after adding 15,300 pounds of trash would be the sum of the empty weight and the weight of the trash:

2.8×10^5 pounds + 1.53×10^4 pounds

To add the two weights, we need to match the powers of 10. We can do this by expressing 1.53×10^4 pounds as 15.3×10^3 pounds:

2.8×10^5 pounds + 15.3×10^3 pounds

Now we can add the numbers:

2.8×10^5 pounds + 15.3×10^3 pounds = 2.8×10^5 pounds + 1.53×10^4 pounds = 2.953×10^5 pounds

Therefore, the dump truck would weigh 2.953×10^5 pounds after adding 15,300 pounds of trash.

Answer 2

The half-life of uranium-235 is 700,000,000 years. The half-life of uranium-238 is 4.463×10^11 years longer. What is the half-life of uranium-238? The answer should be in decimal form.(1 point)