Answer
• Improving the environmental performances
• Developing Green Mining technology
Explanation
The effect to the environment caused by opal mining are; impact on soils and geology, clearing of native vegetation disrupting flora and fauna, change in land use and effects of air quality.
Opal mining is currently examining environmental impacts and adopting measures that mitigate the impacts making the process less destructive to the environment.
With the current commitment to sustainability, opal companies are investing funds for Green Mining as a positive way to impact the environment before and after mining.
Answer:
When an object is dropped, it accelerates toward the center of Earth. Newton's second law states that a net force on an object is responsible for its acceleration. If air resistance is negligible, the net force on a falling object is the gravitational force.
Answer:
to make calculation more easy to get
Explanation:
if you are using chart or calculate Thermodynamic problems you will not never solve this problem with out using data table for thermodynamic
17. a
18. c
19. a
20. c
21. c
<span>A star's motion towards or away from us is detected by the wavelength of the spectral lines.
Because when a star is moving toward us or away from us, the apparent color does not change but there is a change in the wavelength of spectral lines, when the stars are moving towards us, the spectral lines are towards red end and when they are moving away from us the spectral lines are towards the blue end.</span>
