1.
Explain why the Earth can be seen from the space by Astronauts. (2 marks)
Correct Answer
D. The Earth reflected light from the closest star to itself to the Astronauts' eyes.
Explanation
The term "closest star" in option D refers to the Sun.
The term "refracted" in option C means the phenomenon of bending of light ray. (you will learn in secondary 2)
2.
Water covers __________ of the Earth's surface. (2 marks)
Correct Answer
A. 3/4
Explanation
Note!
Although Earth covers a large percentage of water, most of them are not for human consumption.
3.
The Earth rotates _________________.(2 marks)
Correct Answer
B. About its own axis all the time.
Explanation
The Earth rotates all the while without pausing although cannot feel it. The term "axis" is an imaginary line that goes through the centre of the Earth, from the North Pole (N) to the South Pole (S).
4.
The Earth takes __________ to make one complete rotation.(2 marks)
Correct Answer
A. 24 hours
Explanation
The Earth takes 24 hours to make one complete rotation. This is known as a day and is the time it takes for the Earth to rotate once on its axis. This rotation is what causes day and night on Earth.
5.
The Earth takes ____________ to make one revolution around the Sun.(2 marks)
Correct Answer
E. About 365 days
Explanation
The Earth takes about 365 days to make one revolution around the Sun. This is known as a year. The concept of a year is based on the Earth's orbit around the Sun, which takes approximately 365.25 days. To account for this extra quarter of a day, we have leap years every four years, where an extra day is added to the calendar in February.
6.
What is a planet? (2 marks)
Correct Answer
C. A gigantic object that revolves around a star
Explanation
The correct answer is "a gigantic object that revolves around a star." This explanation aligns with the commonly accepted definition of a planet, which is a celestial body that orbits a star, is spherical in shape, and has cleared its orbit of other debris. The term "gigantic" implies that planets are significantly larger than other objects in their orbit, such as asteroids or moons. The term "revolves" indicates that planets move in an elliptical path around their star, rather than simply rotating on their axis.
7.
The Moon revolves around the ______________.(2 marks)
Correct Answer
D. Earth
Explanation
The Moon revolves around the Earth. This is because the Earth's gravitational pull keeps the Moon in orbit around it. The Moon takes approximately 27.3 days to complete one orbit around the Earth. This phenomenon is known as the Moon's revolution around the Earth.
8.
The Moon is the _______________. (2 marks)
Correct Answer
A. Earth's natural satellite
Explanation
A satellite is an object in space that revolves around another object. The term "natural" satellite means that it is already there, nobody have changed it.
9.
The picture above shows a __________.(2 marks)
Correct Answer
E. Gibbous moon
Explanation
The picture above shows a gibbous moon. A gibbous moon is when more than half, but less than fully, of the moon's illuminated surface is visible from Earth. In the picture, we can see that more than half of the moon is illuminated, indicating that it is a gibbous moon.
10.
It takes about ______________ for the Moon to go around the Earth once. (2 marks)
Correct Answer
C. 28 days
Explanation
The correct answer is 28 days because this is the average length of the lunar month, which is the time it takes for the Moon to complete one orbit around the Earth. This duration is also known as the synodic month. During this time, the Moon goes through its different phases, such as new moon, first quarter, full moon, and third quarter, which are visible from Earth.
11.
The changes in the Moon's appearance are known as its ____________.(2 marks)
Correct Answer
B. pHases
Explanation
The changes in the Moon's appearance are known as its phases. The Moon goes through different phases as it orbits the Earth, which are caused by the changing positions of the Moon, Earth, and Sun. These phases include the new moon, crescent moon, first quarter moon, gibbous moon, and full moon. The phases of the Moon are a result of the varying amounts of sunlight that illuminate different parts of the Moon as seen from Earth.
12.
Which planet has the largest mass in the Solar System?(2 marks)
Correct Answer
D. Sun
Explanation
The sun has a diameter of 1.4 million km! The sun is also about 1 200 000 times bigger than the Earth in volume!
13.
How many planets are there in the Solar System if there is an exclusion count of pluto?(2 marks)
Correct Answer
C. 8
Explanation
The Sun and the Moon are not planets (Sun is a star, Moon is Earth's natural satellite) Therefore, there are only eight planets in the solar system namely, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
14.
Why are Man-made satellites important?(i) Communication purposes(ii) Space Exploration(iii) Observations of the Earth(iv) Weather Forecasting (2 marks)
Correct Answer
E. All of the above
Explanation
Man-made satellites are important for various reasons. They are used for communication purposes, allowing people to connect and communicate with each other across long distances. They are also crucial for space exploration, as they enable scientists to gather data and explore outer space. Satellites are also used for observing the Earth, providing valuable information about weather patterns, climate change, and other environmental factors. Additionally, satellites play a vital role in weather forecasting, helping meteorologists predict and monitor weather conditions. Therefore, all the given options (i), (ii), (iii), and (iv) are correct explanations for why man-made satellites are important.
15.
Look at the picture below. What is the purpose of this huge device?(2 marks)
Correct Answer
A. To send information in the form of radio signals to a communication satellite in space
Explanation
The purpose of this huge device is to send information in the form of radio signals to a communication satellite in space.
16.
Patty is 12 years old. How many times has the Earth moved around the Sun since the day he was born?(2 marks)
Correct Answer
B. 12
Explanation
Always remember that the Earth takes 1 year (365 days) to make one complete revolution around the Sun.
17.
The experience of day and night cycle is due to the _____________________ that makes the Sun appear to move across the sky. (2 marks)
Correct Answer
rotation of the earth about its axis
rotation of the earth about its own axis
spinning of the earth about its axis
spinning of the earth about its own axis
Explanation
Ans: rotation/spinning of the earth - not accepted
18.
Look at the picture below.There are lines in between each planet. State the name for this line. (2 marks)
Correct Answer
orbit
Explanation
The lines in between each planet are called orbits. Orbits are the paths that planets and other celestial objects follow as they revolve around a central body, such as a star. These paths are typically elliptical in shape and are determined by the gravitational pull between the objects. The concept of orbits is fundamental in understanding the motion and dynamics of objects in space.
19.
How many rotations about its axis would the Earth have made from Muthu's 12th birthday to his 14th birthday?(2 marks)
Correct Answer
730
Explanation
Mathematics' calculation involved here.
20.
How many revolutions around the Sun would the Earth have made in a decade?(2 marks)
Correct Answer
10
Explanation
in a decade = 10 years