The total weight of both objects : 7.035 x 10⁻⁸ kg
Further explanation
Given
The weight of a grain of sand : 3.5 x 10⁻¹⁰ kg
The weight of one hair from his eyebrow : 7 x 10⁻⁸ kg
Required
The total weight of both objects
Solution
Scientific Notation consists of 2 parts
1. the first part: the first digit followed by the decimal point
2. The second part: the power of 10 (the exponents).which shows the number of digits after the decimal point
To add/subtract, the exponents must be the same and then add/subtract the coefficient
- convert the largest exponent (7 x 10⁻⁸)
7 x 10⁻⁸ = 700 x 10⁻¹⁰
![\tt =(3.5+700)* 10^(-10)\\\\=703.5* 10^(-10)\\\\=7.035* 10^(-8)](https://img.qammunity.org/2021/formulas/chemistry/high-school/bynmpd3nsq4wjyym6q1lfyufeyvqg5d0v2.png)