STAAR Category 2

A steel ball is at one end of a box that is moving forward as shown. The box suddenly stops.

According to Newton’s first law, what happens to the steel ball just after the box stops?

• Because of friction, the ball continues rolling forward at the same speed

• Because of friction, the ball rolls forward at an increased speed.

• Because of inertia, the ball continues rolling forward at the same speed.

• Because of inertia, the ball rolls forward at an increased speed

Which statement best describes an action–reaction force pair in this situation?

• The wall pushes on the skater when the skater pushes on the wall.

• The wheels slow down, and the skater stops.

• The skater exerts a force on the wall, and the wheels exert a force on the floor and begin to turn.

• The friction of the floor decreases when the wheels roll on the floor.

Tags

NGSS.MS-PS2-1

What is the approximate acceleration of the bookshelf?

Tags

NGSS.MS-PS2-2

A student investigates the motion of a toy vehicle. The student graphs 40 seconds of data from the investigation.

Which statement best describes the motion of the toy vehicle during the first 30 seconds of the investigation?

• The vehicle was traveling at a constant speed.

• The vehicle was accelerating at a constant rate.

• The speed of the vehicle was increasing.

• The acceleration of the vehicle was increasing.

Tags

NGSS.MS-PS2-2

Roller coasters are popular attractions at amusement parks. A cart on a roller coaster approaches the highest point on the coaster. As the cart reaches the top, it slows down. Which statement best describes the energy of the roller coaster as it slows down while traveling to the top of the coaster?

• The cart gains both kinetic and potential energy.

• The cart gains kinetic energy and loses potential energy.

• The cart loses kinetic energy and gains potential energy.

• The cart loses both kinetic and potential energy.

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

The diagram shows a duck swimming in a stream in the opposite direction the stream is flowing. The duck pushes against the water, so the water pushes the duck forward with 20 newtons of force. The water also exerts 15 newtons of resistive force against the duck. Which statement best describes the resulting motion of the duck?

• The duck will stop moving.

• The duck will stop and then start moving again.

• The duck will continue moving in its current direction.

• The duck will move in the direction that the stream is flowing.

Tags

NGSS.MS-PS2-2

Students build a circuit. The circuit has wires that connect a battery to a switch and a fan. Which energy transformations happen when the students close the circuit and the blades of the fan begin to spin?

• Chemical to mechanical to electrical

• Electrical to chemical to mechanical

• Chemical to electrical to mechanical

• Mechanical to electrical to chemical

Tags

NGSS.MS-PS3-5

A horse trainer records the distance a horse travels during three different trials.

What is the horse’s average speed in kilometers per minute?

A toy truck is at rest on the floor. Which statement describes the forces acting on the toy truck?

• The forces are balanced so motion occurs.

• The forces are balanced so no motion occurs.

• The forces are unbalanced so motion occurs.

• The forces are unbalanced so no motion occurs.

Tags

NGSS.MS-PS2-2

The arctic fox inhabits northern areas of North America. The same arctic fox is shown in the drawing at different times of the year. What causes this change in fur color?

• The alleles for fur color change as the arctic fox grows older.

• Gene expression for fur color is regulated by latitude.

• The arctic fox has two traits for fur color that are determined at birth.

• Gene expression for fur color is regulated by temperature.

Tags

NGSS.MS-LS1-5