STAAR Practice 2

Students design an experiment to determine how much force is needed to move blocks of wood of different masses slowly across a lab table. Which procedure should students include in their design?

• Conduct five trials, using a different scale to pull each block of wood

• Conduct five trials, pulling a different side of each block each time

• Conduct five trials, using a different table for each trial

• Conduct five trials, pulling each block of wood in the same way for each trial

Characteristics of four unknown materials are shown in the table. Unknown Materials | Material | Magnetic | Flexible | Insulator | |----------|----------|----------|-----------| | W | Yes | Yes | No | | X | No | No | No | | Y | No | No | Yes | | Z | No | Yes | Yes | Which material is MOST LIKELY rubber?

• Material W

• Material X

• Material Y

• Material Z

Black walnut trees produce and release a chemical from their roots that prevents nearby plants of different species from growing. Which statement describes the MOST LIKELY advantage for the black walnut trees of releasing this chemical?

• Less sunlight is needed to produce food.

• Walnuts are protected from animal predators.

• Competition for space and nutrients is decreased.

• The amount of air available to the tree increases.

Students are conducting an experiment to determine how the amount of force needed to drag a wood block across a surface is affected by the type of surface. A diagram of the experimental setup is shown. Which procedure should the students follow when conducting their experiment?

• A) Measure the force required to drag four different blocks over the same surface. Conduct three trials for each block.

• B) Measure the force required to drag the same block over four different surfaces. Conduct three trials for each surface.

• C) Measure the force required to drag the same block over the same surface using four different scales. Conduct three trials for each scale.

• D) Measure the force required to drag the same block over the same surface by four different students. Conduct three trials for each student.

Students watch a video about monarch butterflies. A list of behaviors the students observe about the monarch butterflies is shown. 1. Laying eggs on a milkweed leaf 2. Sitting in the sun to dry their wings 3. Drinking nectar from a bright red flower 4. Landing on a rock near a bush 5. Migrating south in the winter Which observations show monarch butterflies interacting with living parts of the environment?

• A. Observations 4 and 5

• B. Observations 1 and 3

• C. Observation 5 only

• D. Observation 2 only

A student conducted an investigation about density. The materials used were Water, Liquid 2, Object X, and Object Y. The results of the investigation are shown. Which option shows the correct order of the materials from lowest to highest density?

• Object X, Object Y, Water, Liquid 2

• Water, Liquid 2, Object X, Object Y

• Water, Object X, Liquid 2, Object Y

• Object X, Water, Object Y, Liquid 2

Students investigate the physical properties of some substances. They draw a table to show how the substances can be grouped. The students need to complete the table with column headings. Physical Properties of Substances - Aluminum foil - Brass key - Gold ring - Cooking oil - Soap bubble - Wood chip - Feather - Baking soda - Drink mix - White sugar Which column headings should the students use for their table?

• Good Insulators of Thermal Energy, Is Attracted by Magnets, Same Physical State

• Good Conductors of Electrical Energy, Less Dense than Water, Soluble in Water

• Soluble in Water, Same Physical State, Less Dense than Water

• Is Attracted by Magnets, Good Conductors of Electrical Energy, Good Insulators of Thermal Energy

Students conduct experiments to investigate friction. Which experiment will best test the effect of friction on objects?

• Drop two balls from the same height at the same time

• Roll two marbles on the carpet from the same starting point at the same time and with the same amount of force

• Roll three marbles across three different surfaces from the same starting point at the same time and with the same amount of force

• Release two balls from the top of a ramp at the same time

A student places objects in a bucket of water to determine if they will float. Which set of items is less dense than water?

• Plastic paper clip, penny, and cork

• Toothpick, metal spoon, and plastic paper clip

• Metal spoon, vegetable oil, and penny

• Toothpick, cork, and vegetable oil

The diagrams show two trials of an experiment in which a spring scale was used to measure force. This experiment can be used to determine —

• how mass affects the force needed to move objects

• how force affects the mass of two objects

• how the force used to pull a dictionary affects the mass of a box of marbles

• how the mass of a box of marbles affects the mass of a dictionary