3rd 9 weeks Physics Test for 8th Grade

According to the principles of physical and chemical changes, a substance in its physical state tends to remain in that state and a substance undergoing a chemical change tends to continue the reaction unless acted upon by an external condition. True or False?

• False

• Maybe

• True

• Sometimes

What is the formula for calculating work done when pushing a block across the floor?

• Work = Force x Distance

• Work = Mass x Acceleration

• Work = Velocity x Time

• Work = Energy x Power

What is the SI unit of electric current used in charging a smartphone?

• C

• D

• B

• A

What type of change is burning of wood?

• Physical change

• Chemical change

• State change

• Mechanical change

What is the process called when heat is transferred from a hot pan to an egg, cooking it, through direct contact?

• induction

• radiation

• convection

• conduction

Which is the smallest unit of matter that retains the properties of an element during physical and chemical changes?

• molecule

• cell

• nucleus

• atom

Which of the following is an example of a chemical change?

• Boiling water

• Dissolving sugar in water

• Crushing a can

• Burning wood

When heating sugar in a pan until it caramelizes, which formula represents the change in its state due to the applied heat?

• F = mv

• F = a/m

• F = m^2a

• F = ma

What is the unit of measurement for the frequency at which water boils into steam?

• Watt

• Ampere

• Hertz (Hz)

• Volt

In the process of water boiling and condensing back into a container, which law is being demonstrated?

• Water can be created out of nothing during boiling

• Water can be transformed into a completely different substance

• Water cannot be created or destroyed, only transferred or transformed.

• Water can be destroyed completely during boiling