Physical Science Semester Review Test

David and Priya are studying the gravitational force between two planets. What is the equation for calculating the gravitational force between them?

• F=G(m₁m₂/d²)

• F=m×a

• F=m/a

• None of the above

Answer explanation

The correct equation for calculating the gravitational force between two masses is F=G(m₁m₂/d²), where G is the gravitational constant, m₁ and m₂ are the masses, and d is the distance between their centers.

Tags

NGSS.HS-PS2-4

Noah and Abigail are trying to understand how the gravitational force between two objects can be changed. What factors can they alter to achieve this?

• By changing the masses of the objects and the distance between them

• By changing the acceleration of the objects

• By changing the direction of the objects’ motion

• By changing the speed of the objects

Answer explanation

The gravitational force between two objects is determined by their masses and the distance between them, as described by Newton's law of universal gravitation. Changing these factors directly affects the gravitational force.

Tags

NGSS.MS-PS2-2

NGSS.MS-PS2-4

Emma is observing a comet as it moves away from the sun. What happens to the comet’s speed as its distance from the sun increases?

• It increases

• It decreases

• It stays constant

• None of the above

Answer explanation

As a comet moves away from the sun, the gravitational pull decreases, leading to a decrease in its speed. Therefore, the correct answer is that the comet's speed decreases as its distance from the sun increases.

Tags

NGSS.MS-ESS1-2

NGSS.MS-PS2-4

Elijah and Luna are working on a school project about sustainable practices. They decide to explore composting. What are some benefits of composting?

• Improved soil health and nutrient recycling

• Soil damage and loss of crops

• Increased use of non-renewable resources

• Production of harmful waste materials

Answer explanation

Composting improves soil health by adding organic matter, which enhances nutrient recycling. This leads to better crop yields and reduces the need for chemical fertilizers, making it a sustainable practice.

Tags

NGSS.MS-ESS2-1

NGSS.MS-LS2-3

NGSS.MS-LS2-5

Priya is learning about composting in her environmental science class. She wonders, what is the role of energy in the composting process?

• Energy is transferred but not created or lost (Law of Conservation of Energy)

• More energy is consumed than produced

• Less energy is required for composting

• None of the above

Answer explanation

In composting, energy is transferred through microbial activity, adhering to the Law of Conservation of Energy, which states that energy cannot be created or lost, only transformed.

Tags

NGSS.MS-LS2-3

NGSS.MS-PS3-5

Hannah and Samuel are learning about composting in their science class. They want to know if composting involves a physical or chemical change. What would you tell them?

• Physical change only

• Chemical change only

• Both physical and chemical changes

• Neither physical nor chemical changes

Answer explanation

Composting primarily involves a chemical change as organic materials decompose and transform into nutrient-rich compost through microbial activity, resulting in new substances. Thus, the correct answer is 'Chemical change only'.

Tags

NGSS.MS-LS2-3

NGSS.MS-PS1-2

NGSS.MS-PS1-5

During a classroom discussion on vehicle safety, Maya asked, "Which of the following is NOT a vehicle safety feature?"

• Steering wheel

• Exhaust system

• Seat belt

• Airbags

Answer explanation

The exhaust system is not a safety feature; it primarily manages emissions. In contrast, the steering wheel, seat belts, and airbags are essential for vehicle safety.

Grace is working on a school project about recycling. She wants to know which of the following inorganic materials is most commonly recycled into new products due to its properties?

• Plastic

• Aluminum

• Cardboard

• Organic waste

Answer explanation

Aluminum is the most commonly recycled inorganic material due to its ability to be recycled indefinitely without losing quality. It is highly efficient to recycle, making it a preferred choice for new products.

Tags

NGSS.MS-PS1-3

During a school project on waste management, Olivia and Noah discovered that inorganic waste primarily contributes to environmental problems because it:

• Decomposes too quickly, releasing harmful substances

• Releases harmful organic chemicals into the environment

• Takes a long time to break down naturally, occupying landfill space

• Is too lightweight and difficult to dispose of properly

Answer explanation

Inorganic waste takes a long time to break down naturally, leading to significant landfill space occupation. This contributes to environmental problems, unlike organic waste, which decomposes more quickly.

Hannah is working on a school project about recycling and wants to know the main process used to recycle aluminum cans, ensuring they can be reused in products such as new cans. What process should she focus on?

• Shredding and melting

• Grinding and composting

• Crushing and heating without melting

• Breaking down chemically

Answer explanation

Hannah should focus on shredding and melting, as these are the key steps in recycling aluminum cans. Shredding breaks the cans into smaller pieces, and melting transforms them into molten aluminum for reuse in new products.

Tags

NGSS.MS-PS1-2