8th Grade Practice Exam

An elevator is supported by a cable and is moving downward through the elevator shaft at constant speed.

How does the upward tension force in the cable compare to the downward force of gravity?

• The only force acting on the elevator is the force of gravity because it is moving downward.

• The upward tension force in the cable is greater than the downward force of gravity.

• There are no forces acting on the elevator because it is moving at constant velocity.

• The upward tension force in the cable is equal to the downward force of gravity.

Tags

NGSS.MS-PS2-2

NGSS.MS-PS2-4

A student adds a fruit flavored energy mix to his water. Soon the water is the color of the energy mix.

Which statement BEST compares the drink the student has made to air?

• It is a mixture like air because the components are of the same particles.

• It is a mixture like air because the components cannot be physically separated.

• It is a mixture like air because the components are chemically combined.

• It is a mixture like air because the components can be physically separated.

A group of students were investigating the effects of different modes of heat transfer and observed ice melting in a beaker that was sitting on a hot plate.

Which mode of heat transfer is responsible for heat flowing from the hot plate to the glass beaker?

• convection

• radiation

• conduction

• insulation

Which argument supports the Law of Conservation of Energy within a system?

• Energy cannot be changed or destroyed.

• Energy cannot be created.

• Energy cannot be created or destroyed.

• Energy cannot be changed.

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-4

Which energy transformation occurs when you strike (light) a match?

• chemical to heat

• heat to light

• mechanical to heat

• light to heat

Light radiates from the sun, and trees transform the light energy into ATP molecules through the process of photosynthesis.

• electrical energy

• mechanical energy

• kinetic energy

• chemical energy

Tags

NGSS.MS-LS1-6

NGSS.MS-LS2-3

Solar panels are becoming a source of energy that many people are using to power their home.

Which of the following arguments BEST explains how solar panels can power a home?

• Solar panels transform the light energy from the Sun into electrical energy that can be used in the home.

• Solar panels transform the chemical energy from the Sun into electrical energy that can be used in the home.

• Solar panels transform the thermal energy from the Sun into light energy that can be used in the home.

• Solar panels transform the thermal energy from the Sun into chemical energy that can be used in the home.

If you have a slice of pizza and a glass of milk, which BEST explains how pizza differs from milk?

• Pizza is a suspension, and milk is a solution.

• Pizza is a mixture, and milk is a compound.

• Both are mixtures; pizza is heterogeneous, and milk is homogeneous.

• Both are solutions; pizza’s components can be seen, and milk’s components cannot be seen.

Kala wanted to classify common household materials as pure substances and mixtures. She collected as many things from around her house as possible and made two lists. Kala’s friend thinks that she made a mistake.

Pure Substances: Sugar, Salt, Baking soda, Milk, , and Water

Mixtures: Laundry detergent, Chalk, Glass cleaner, Shampoo, and Butter.

What change can Kala make to her list that will correct her mistake?

• Kala should place sugar in the list of mixtures, and butter in the list of pure substances.

• Kala should place milk in the list of mixtures, and chalk in the list of pure substances.

• Kala should place milk in the list of mixtures, and shampoo in the list of pure substances.

• Kala should place baking soda in the list of mixtures, and chalk in the list of pure substances.

Julie was ironing her clothes for school and noticed when she hung up the ironed clothes they were still hot from being ironed. She decided to investigate the heat change that occurred when the clothes were being ironed.

Which of the following BEST explains how the heat was transferred to increase the temperature of the clothing?

• The temperature of clothing increased because the thermal energy of the iron was transferred to the clothing by the thermal energy traveled through space to heat the clothing.

• The temperature of the clothing increased because the thermal energy of the iron was transferred to the clothing by the collision of the atoms in the iron and in the clothes.

• The temperature of clothing increased because the thermal energy of the iron was transferred to the clothing by the thermal energy rose to the clothing causing the clothes to be heated.

• The temperature of clothing increased because the thermal energy of the iron was transferred to the clothing by electrical energy traveled to the clothes through the iron causing the temperature of the clothes to increase.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4