Question

20. Lines on a map that run parallel to the equator are known as

Answer 1

The answer to question 20 is C. Lines of latitude run parallel to the equator, appearing horizontal on a globe. The answer to question 18 is B - astronomy is a science that studies celestial bodies, and applies work from astrophysics and planetary science. Question 13's answer is D. Weight is the measure of gravitational force on an object and is measured in Newtons. The answer to question 12 is D. The independent variable is the variable the investigator changes to ascertain how this impacts on the dependant variable. The answer to question 11 is B. The classification of magma as basaltic, andesitic or rhyolitic depends on the percentage of silica it contains. The answer to question 10 is B. The particles in metal are held together by metallic bonds which involve closely packed ions and electrons that are free to move about and conduct electricity. The answer to question 3 is D. There are currently more than 24 GPS satellites in orbit, but this is the number that are operational most of the time. The answer to question 2 is B. The dependent variable is affected by the independent variable - it depends on the independent variable.

Answer 2

1. Answer;

Lines of latitudes  

Lines on a map that run parallel to the equator are known as lines of latitude.

Explanation;

• Lines of latitudes are imaginary lines that run from east to west and measure north-south position between the poles.  
• Lines of latitudes are parallel to each other. The equator is zero degrees, while the North Pole is 90 degrees north and the South Pole is 90 degrees south.  
• Lines of longitudes or meridians on the other hand are imaginary lines that run between the North and South poles. They measure east-west position.

2. Answer;

B. astrophysics and planetary science

The two sub-specialties of astronomy are astrophysics and planetary science.

Explanation;

• Astronomy is a science that studies objects beyond the earth's atmosphere, such as planets, stars, asteroids, galaxies; and the properties and relationships of those celestial bodies.  
• Astrophysics involves the application of physics to understand astronomy. It involves the study of actual physical processes taking place in the universe, such as how they operate, etc
• Planetary science is the scientific study of planets, such as the earth and other planets in our solar system, moons, and planetary systems and the processes that form from them.

3. Answer;

D. a measure of gravitational force on an object.

Explanation;

• The weight of an object refers to the measure of the force exerted by gravity on the object. Weight will therefore depend on the gravitational force on a surface, and will vary from one place to another, such that the weight of an object on earth surface will be different on the moon’s surface.
• Weight is measured using a spring balance and is measured in Newton (N).

4. Answer;

D. The factor that's changed by the experimenter and impacts the dependent variable

Explanation;

• An independent variable is the variable that is changed or controlled by the experimenter in a scientific experiment to test the effects on the dependent variable.
• A dependent variable on the other hand is the variable being tested and measured in a scientific experiment. Dependent variable in an experiment changes from the manipulation of the independent variable.
• As the experimenter manipulates or varies the independent variable, the effect seen on the dependent variable is observed and recorded.

5. Answer;

B. Amount of silica it contains

Magma is classified as basaltic, andesitic, or rhyolitic based on the amount of silica it contains.

Explanation;

• Magma is defined as a molten and semi-molten mixture that is found under the surface of the Earth. Intrusive igneous rocks are formed from the magma that cools and solidifies within the earth’s crust, surrounded by an already existing rock.  
• Silica (SiO2) is the primary oxide present in magmatic rocks and serves as the basis of classifying magmatic rocks broadly.  

6. Answer;

Metallic bond

A metallic bond allows metals to conduct electricity.

Explanation;

• Metallic bonds are types of bonds or forces of attraction that occurs between the positive ions of metal and valence electrons known as sea of electrons that are constantly in motion around the positive ions.  
• The metal positive ions forms a lattice like-metallic structure that is held together by metallic bond. Metals conducts electricity as a result of mobile electrons which are free to move towards any direction.

7. Answer;

24  

There are 24 GPS satellites orbiting the Earth.

Explanation;

• The baseline satellite constellation contains 24 satellites which are positioned in six earth-centered orbital planes with four operation satellites and a spare satellite slot in each orbital plane.
• The 24 main GPS satellites orbit Earth every 12 hours, sending a synchronized signal from each individual satellite. A User will receive signals at slightly different times since the satellites are moving in different directions.

8. Answer;

B. dependent variable

Explanation;

• A dependent variable is the variable or a factor that is being tested and measured in a scientific experiment. An independent variable on the other hand is the variable or a factor that is changed or controlled by the experimenter in a scientific experiment to test the effects on the dependent variable.
• Dependent variable in an experiment changes from the manipulation of the independent variable.
• As the experimenter manipulates or varies the independent variable, the effect seen on the dependent variable is observed and recorded.