5.7AB STAAR Practice

Hayden and Jaiden are conducting an investigation in their classroom using a small toy car attached to a balloon inflated with air. The balloon is secured to the car with a straw that directs the escaping air backward toward a wall. When Jaiden releases the straw, the air rushes out of the balloon in a strong stream directed toward the wall, causing the car to move forward across the smooth classroom floor. This setup demonstrates a classic example of how forces interact to produce observable patterns of motion. Based on the principles of equal and unequal forces acting on the system, which statement best explains the motion of the car immediately after the straw is released?

• The car will remain stationary because the force of the escaping air is balanced by the friction from the floor acting in the opposite direction.

• The car will move toward the wall in the same direction as the escaping air due to the unbalanced force pulling it forward.

• The car will move away from the wall in the direction opposite to the escaping air because the reaction force propels it forward.

• The car will spin in place without translating linearly because the air's force is distributed unevenly across the car's surface.

Orin, Ryley, and Danny are designing an experiment to explore the effects of friction as a force influencing the motion of spherical objects. They plan to roll identical marbles from the same starting point using the same initial push force, but they want to isolate the variable of surface texture to observe differences in how far each marble travels before stopping. To ensure their investigation accurately tests the impact of friction on patterns of motion, which experimental procedure should the group follow?

• Roll two identical marbles on a smooth tile floor simultaneously and measure the distance each travels.

• Drop two marbles from the same height above the floor at the same time and compare their landing speeds.

• Roll three identical marbles across three different textured surfaces—such as carpet, wood, and sandpaper—from the same starting point with the same force, recording the distance each travels in three trials per surface.

• Release two marbles from the top of an inclined ramp at the same time and note which one reaches the bottom first.

Luke is observing a wooden wagon loaded with several heavy textbooks during recess on the playground. He gives the wagon a firm push in a forward direction, causing it to accelerate initially across the paved surface. However, as the wagon continues along its path, it gradually slows down and eventually comes to a complete stop without any additional input from Luke. This scenario illustrates how various forces interact to alter an object's motion over time. What force is primarily responsible for causing the wagon to decelerate and stop after the initial push?

• The force of gravity pulling downward on the wagon, acting in the same direction as the initial push to maintain constant speed.

• The force of friction between the wagon's wheels and the pavement, acting opposite to the direction of motion to oppose forward movement.

• The force of gravity acting upward on the wagon to balance the downward pull and prevent any change in speed.

• The force of friction acting in the same direction as the push to increase the wagon's acceleration.

Emori and Kennedy are working together in the science lab to test how the angle of an incline affects the amount of force required to pull objects up a ramp. They have set up a wooden ramp with a spring scale attached to a stack of metal masses placed at the bottom. The ramp can be adjusted to different heights, and they measure the force reading on the scale as they pull the masses upward at a constant slow speed. To determine what change would most effectively reduce the force needed to move the masses up the ramp while keeping all other variables constant, which adjustment should they make?

• Increase the height of the ramp to create a steeper incline, thereby decreasing the gravitational component parallel to the ramp.

• Add an extra mass to the stack to increase the total weight, making it easier for the spring scale to register lower force.

• Decrease the height of the ramp to create a gentler incline, reducing the component of gravity opposing the pull.

• Pull the spring scale using both hands simultaneously to distribute the effort and lower the measured force.

Mason is carefully watching a small plastic toy car during a physics demonstration in class. The car is placed at the top of a sloped ramp made from a piece of cardboard propped against a desk. When released, the car accelerates downward along the ramp, gaining speed as it descends. Upon reaching the flat classroom floor at the bottom, the car continues rolling but begins to slow down noticeably before coming to a halt several feet away. This observation highlights the roles of different forces in influencing an object's velocity and direction of travel. Which combination of forces best describes what caused the car to accelerate down the ramp and then decelerate across the floor?

• Friction caused the acceleration down the ramp, while gravity caused the deceleration on the floor.

• Gravity caused the acceleration down the ramp, while friction caused the deceleration on the floor.

• Friction caused both the acceleration down the ramp and the deceleration on the floor.

Jake and Gio are planning a controlled experiment in their school's makerspace to investigate how varying surface types influence the force required to drag a rectangular wooden block across a horizontal plane. They have access to a digital force sensor connected to a string attached to the block, and they intend to pull the block at a constant slow speed to measure the peak force needed for motion to begin on each surface. To properly design their investigation so that it isolates the effect of surface friction on the block's motion while ensuring reliable data, which step should they include in their procedure?

• Measure the force needed to drag four different-sized blocks across the same smooth tabletop, repeating three trials for each block.

• Measure the force needed to drag the same block across four distinct surfaces—like tile, carpet, wax paper, and rough sandpaper—repeating three trials for each surface with identical pulling technique.

• Measure the force needed to drag the same block across the same surface using four different force sensors, repeating three trials for each sensor.

• Measure the force needed to drag the same block across the same surface by having four different classmates pull it, repeating three trials for each puller.

Brelyn and Sage are collaborating on a group activity where they must transport a low cart filled with a collection of library books from one end of the classroom to the other. The cart features handles on both the front and back sides, allowing for pulling or pushing actions. Brelyn positions herself at one end, while Sage stands at the other. To minimize the effort required and achieve the smoothest possible motion with the least resistance from unbalanced forces, which coordinated actions should Brelyn and Sage perform?

• Brelyn pulls the cart toward her while Sage pulls the cart toward himself, creating balanced opposing forces.

• Brelyn pushes the cart away from her while Sage pushes the cart downward, applying perpendicular forces.

• Brelyn pulls the cart toward her while Sage pushes the cart in the same direction, combining forces to produce net forward motion.

• Brelyn pushes the cart away from her while Sage pulls the cart upward, introducing vertical components that cancel horizontal motion.

Autry is performing a materials-testing investigation using a lightweight paper cup suspended from a taut string that is looped over an uncooked spaghetti noodle stretched between two stable chairs approximately one meter apart. Autry begins by recording the precise mass of a single penny using a digital balance. Then, Autry systematically adds pennies to the cup one by one, observing the noodle's response after each addition until it snaps under the increasing load. This setup allows for quantitative measurement of how applied force correlates with structural failure. What is the primary question Autry is most likely attempting to answer through this carefully controlled investigation?

• How many pennies can the string support before it stretches beyond its elastic limit?

• How does the distance between the chairs influence the breaking point of the paper cup?

The additional mass from pennies required to generate sufficient downward force to fracture the spaghetti noodle is:

• The minimum mass that causes the noodle to break

• Any amount of mass

• The mass of a single penny

• Twice the mass needed to break the noodle

The string must be how long to maximize the number of pennies the system can hold without tipping?

• As long as possible without causing tipping

• Shorter than the length of the lever arm

• Exactly equal to the length of the lever arm

• Half the length of the lever arm