Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Gravity is the invisible force that pulls objects toward the center of the Earth. It is what keeps our feet on the ground and gives objects weight.
In space, specifically inside the International Space Station (ISS), astronauts experience a state called 'microgravity' or weightlessness. This is why they and their belongings float.
Astronauts like Sunita Williams have shared that in space, simple tasks like eating and washing require special techniques. Food must be kept in packets to prevent it from floating away, and water forms into floating 'blobs' due to surface tension and lack of gravity.
The Earth's atmosphere provides the (Oxygen) necessary for life and protects us from harmful solar radiation. Space is a vacuum, meaning there is no air to breathe.
From space, the Earth looks like a beautiful blue marble. Oceans cover about of the surface. National borders are not visible from space; only landmasses and water bodies can be seen.
Exercise is crucial for astronauts. Because there is no gravity to work against, muscles and bones can become weak. They must exercise for about hours every day.
📐Formulae
💡Examples
Problem 1:
If an astronaut has a mass of on Earth, what would be their mass on the Moon?
Solution:
Explanation:
Mass is the amount of matter in an object and remains constant everywhere in the universe. Only the weight () changes depending on the gravitational pull ().
Problem 2:
Calculate the approximate weight of a bag of space supplies on Earth using .
Solution:
Explanation:
Weight is the force of gravity acting on an object. It is measured in Newtons () by multiplying mass () by the acceleration due to gravity ().
Problem 3:
Why do astronauts have to strap themselves into their beds while sleeping in the ISS?
Solution:
To prevent floating away.
Explanation:
Because of the state of microgravity ( relative to the station), there is no force keeping the astronaut's body on a mattress. Straps are used to keep them stationary so they don't bump into equipment while asleep.