Type of Forces
What is the force that pulls objects towards the centre of the Earth?
Gravity
What is the difference between volume and pitch in sound?
Volume refers to how loud or soft a sound is, while pitch refers to how high or low the sound is.
What is a magnet?
A magnet is a material that produces a magnetic field, which can attract or repel other magnetic materials.
What is the name of the process by which plants use sunlight to make their own food?
Photosynthesis.
What is the capital of the United States?
Washington, D.C.
What is the force that resists motion between two surfaces that are in contact with each other?
Friction
How does sound travel through different materials, such as water or steel?
Sound travels faster through denser materials, such as water or steel, than it does through air. This is because the particles in these materials are closer together, which allows the sound waves to travel more quickly.
What is the difference between a permanent magnet and a temporary magnet?
A permanent magnet is a magnet that retains its magnetism over a long period of time, while a temporary magnet is a magnet that only retains its magnetism while it is in the presence of a magnetic field.
What is the difference between a solid, a liquid, and a gas?
A solid has a fixed shape and volume, a liquid has a fixed volume but takes the shape of its container, and a gas has neither a fixed shape nor a fixed volume.
Who wrote the Harry Potter series of books?
J.K Rowling
Explain in your own words what air resistance is and provide two examples of how it affects objects in motion.
Air resistance is the force that opposes the motion of objects as they move through the air. When an object moves through the air, the air molecules push against the object, making it harder for the object to move forward. This force can cause objects to slow down or change direction. Examples of how air resistance affects objects in motion include a parachute slowing down a falling skydiver or a bird soaring through the air.
Pumla is having a practice before her solo concert next week. Her neighbourhood is complaining because of the very loud sounds she made. Suggest three ways for Pumla so that the sounds of her practice can be muffled.
- Use Acoustic foam to absorb the sounds
- Carpet - Carpeting can help absorb sound waves and reduce echo in a room.
- Curtains or drapes - Heavy curtains or drapes can help absorb sound waves and reduce noise in a room.
Pumla wants to investigate how the size of magnets can affect the number of iron nails it attracts.
what is the independent variable of her investigation?
the size of magnets
What is the difference between a chemical change and a physical change? Give an example of each.
A chemical change is a change that produces a new substance with different properties than the original substance, while a physical change is a change that does not produce a new substance. An example of a chemical change is the reaction between baking soda and vinegar, which produces carbon dioxide gas. An example of a physical change is melting ice, which changes from a solid to a liquid without producing a new substance.
What is the largest continent by land area?
Asia.
What is the effect of an unbalanced force on an object?
An unbalanced force causes an object to move faster or change direction.
How do vibrations produce sound?
Vibrations produce sound by creating waves of pressure in the air. When an object vibrates, it compresses and expands the air around it, creating a wave of high and low pressure that spreads out from the object. Our ears detect these waves and interpret them as sound.
How can you ensure that your experiment with magnets is a fair test?
To ensure that an experiment with magnets is a fair test, you should keep all other variables constant except for the variable you are testing, use the same type and strength of the magnet in each trial, and use the same distance and orientation between the magnets in each trial.
What is the difference between renewable and nonrenewable resources? Give an example of each.
Renewable resources are resources that can be replenished over time, such as solar power or wind power. Nonrenewable resources are resources that cannot be replenished over time, such as fossil fuels like oil or coal.
What is the name of the largest ocean in the world?
Pacific Ocean.
What is water resistance, and how does it affect objects that move through the water? Provide two examples to support your answer.
Water resistance is the force that opposes the motion of objects as they move through water. When an object moves through water, the water molecules push against the object, making it harder for the object to move forward. This force can cause objects to slow down or change direction. Examples of how water resistance affects objects that move through water include a swimmer moving through the water or a boat moving through the ocean.
How do musical instruments produce different pitches?
Musical instruments produce different pitches by creating vibrations of different frequencies. For example, a shorter string on a guitar will vibrate more quickly than a longer string, producing a higher pitch.
What is the magnetic field of the Earth called?
The geomagnetic field.
What is the greenhouse effect, and how does it contribute to global warming?
The greenhouse effect is a natural process that occurs when certain gases in the Earth's atmosphere, such as carbon dioxide and methane, trap heat from the sun and prevent it from escaping into space. This process helps to keep the Earth warm and livable, but when the levels of these gases in the atmosphere increase due to human activity, it can lead to global warming.
Who painted the Mona Lisa?
Leonardo da Vinci.