Pushes and pulls Transitional Reasoning Practice

Questions

1. 1.

   In an automated distribution center, an engineer evaluates two robotic sorting arms positioned alongside a conveyor belt to redirect packages. Arm 1 uses an expanding piston that presses firmly against a package to propel it away from the arm into a sorting bin. Arm 2 uses a suction gripper that latches onto a package and retracts inward to draw it toward the arm into a side channel. Which statement correctly classifies the contact force applied by each robotic arm and explains its effect on the package's motion relative to the arm?

   • A) Arm 1 exerts a push that accelerates the package away from the arm, whereas Arm 2 exerts a pull that accelerates the package toward the arm.
   • B) Arm 1 exerts a pull that accelerates the package away from the arm, whereas Arm 2 exerts a push that accelerates the package toward the arm.
   • C) Arm 1 exerts a push that accelerates the package toward the arm, whereas Arm 2 exerts a pull that accelerates the package away from the arm.
   • D) Arm 1 exerts a pull that accelerates the package toward the arm, whereas Arm 2 exerts a push that accelerates the package away from the arm.
2. 2.

   A student investigates how forces can act at a distance using two wheeled carts with bar magnets fixed to their tops. In Experiment 1, the student holds the north pole of one magnet near the north pole of the second cart, causing the second cart to roll away from the magnet without touching it. In Experiment 2, the student presents the south pole to the north pole of the second cart, causing it to roll closer toward the magnet without touching it. Which statement correctly classifies the type of force acting on the second cart in each experiment?

   • A) Experiment 1 demonstrates a push because like magnetic poles repel and force the cart away, while Experiment 2 demonstrates a pull because opposite magnetic poles attract and draw the cart closer.
   • B) Experiment 1 demonstrates a pull because like magnetic poles resist each other, while Experiment 2 demonstrates a push because opposite magnetic poles compress together.
   • C) Both experiments demonstrate pushes because non-contact forces can only drive objects outward away from a magnetic source.
   • D) Both experiments demonstrate pulls because magnets can only attract objects and cannot exert forces without direct physical contact.
3. 3.

   A student wearing roller skates stands stationary on a smooth, level rink while facing a rigid perimeter barrier. In Action 1, the student places their flat palms against the barrier and straightens their arms to press firmly against it. In Action 2, the student grips a fixed handrail on the barrier and bends their arms to draw their body closer to the barrier. Which statement correctly identifies the type of contact force the student exerts on the barrier in each action and describes the student's resulting motion?

   • A) In Action 1, the student exerts a pull on the barrier and rolls toward it; in Action 2, the student exerts a push on the barrier and rolls away from it.
   • B) In Action 1, the student exerts a pull on the barrier and rolls away from it; in Action 2, the student exerts a push on the barrier and rolls toward it.
   • C) In Action 1, the student exerts a push on the barrier and rolls toward it; in Action 2, the student exerts a pull on the barrier and rolls away from it.
   • D) In Action 1, the student exerts a push on the barrier and rolls away from it; in Action 2, the student exerts a pull on the barrier and rolls toward it.
4. 4.

   A student flies a kite outdoors on a windy afternoon and holds the tether string firmly so the kite remains stationary in the air. The moving air presses against the broad surface of the kite's fabric, while the taut string connects the kite to the student's hand. Which statement correctly classifies the contact force exerted by the air on the fabric and the contact force exerted by the taut string on the kite?

   • A) The air exerts a pull because it draws the kite along with its flow, while the string exerts a push because it props the kite up away from the student.
   • B) The air exerts a pull because it lifts the kite into the sky, while the string exerts a pull because tension draws the kite toward the student.
   • C) The air exerts a push because it presses against the fabric surface, while the string exerts a pull because tension draws the kite toward the student.
   • D) The air exerts a push because it presses against the fabric surface, while the string exerts a push because it holds the kite away from the ground.
5. 5.

   During a science investigation, a student observes a solid sphere rolling across a smooth, level floor in a straight line from west to east. As the sphere passes, the student uses a flat paddle to firmly press against the sphere's south side, exerting a force directed toward the north. Which statement correctly identifies the type of force applied and describes its effect on the sphere's motion?

   • A) It is a pull directed toward the paddle, causing the sphere to speed up along its original eastward line.
   • B) It is a push directed away from the paddle, causing the sphere to deflect northeast and change its direction.
   • C) It is a pull directed away from the paddle, causing the sphere to stop immediately and reverse toward the west.
   • D) It is a push directed toward the paddle, causing the sphere to slow down along its original eastward line.
6. 6.

   During an investigation on forces and motion, a student stands stationary at the end of a straight track as a wheeled cart rolls directly toward her. She plans to apply a contact force to the front of the cart from her fixed position to either increase or decrease its forward speed. Which statement correctly explains how she should apply a push or a pull to achieve these outcomes?

   • A) Pushing the cart away from herself will increase its speed because pushes always accelerate moving objects, while pulling it toward herself will decrease its speed.
   • B) Pulling the cart toward herself will decrease its speed because pulling always resists forward motion, while pushing it away from herself will increase its speed.
   • C) Pulling the cart toward herself applies a force in the direction of its motion to increase its speed, while pushing it away from herself applies an opposing force to decrease its speed.
   • D) Both pushing and pulling from her position apply forces that act opposite to the cart's motion, so both actions will decrease its speed.
7. 7.

   During a laboratory investigation on contact forces, a student interacts with a horizontal spring anchored at one end to a rigid wall. In the first step, the student presses their hand firmly against the free end toward the wall, compressing the spring. In the second step, the student grips the free end and draws it outward toward their body, stretching the spring. Which statement correctly identifies the types of forces applied by the student in each step?

   • A) The first step applies a pull and the second step applies a pull, because any contact force that deforms an elastic object is classified as a pull.
   • B) The first step applies a pull because the student's hand moves inward, while the second step applies a push because the spring expands in total length.
   • C) The first step applies a push because the force is directed away from the student toward the wall, while the second step applies a pull because the force is directed toward the student.
   • D) The first step applies a push and the second step applies a push, because both actions require the student to exert active physical effort to overcome the spring's resistance.
8. 8.

   A student stands upright over a stationary floor pump to inflate a basketball. In the first stroke, the student presses down on the crossbar handle to move it toward the base on the floor. In the second stroke, the student grips the handle and lifts it upward toward their torso to refill the pump chamber. Which statement correctly identifies the types of forces applied to the handle during these two strokes?

   • A) Pressing the handle downward is a pull because it compresses the air inside, while lifting the handle upward is a push because it expands the chamber.
   • B) Pressing the handle downward is a push because the force is directed away from the student, while lifting the handle upward is a pull because the force is directed toward the student.
   • C) Both actions are pushes because the student maintains continuous physical contact with the crossbar throughout both movements.
   • D) Both actions are pulls because the handle always resists the student's motion due to internal air pressure.
9. 9.

   Two students work together to move a stalled utility cart forward across a flat workshop floor. Marcus stands behind the cart with his palms flat against its back panel, exerting force directed away from his body. At the same time, Elena stands ahead of the cart facing forward while gripping a tow handle, exerting force directed toward her body. Which statement correctly identifies the types of forces Marcus and Elena apply and explains their combined effect on the cart?

   • A) Marcus exerts a push and Elena exerts a pull, and because both forces act in the forward direction, they combine to move the cart forward.
   • B) Marcus exerts a pull and Elena exerts a push, and because the two forces act in opposite directions, they cancel each other out.
   • C) Both Marcus and Elena exert pushes, because any applied force that moves an object forward across a floor is classified as a push.
   • D) Marcus exerts a push and Elena exerts a pull, but the cart cannot move because a push and a pull cannot act in the same direction.
10. 10.

    Maya investigates how forces affect the motion of a toy car that is currently rolling forward and moving away from her along a straight track. To slow the car down, stop it, and bring it back toward herself using an attached string, she must exert a force on the car. Which statement correctly identifies the action and explains the type of force being applied?

    • A) She must pull the string toward herself, because a pull is a force directed toward the person exerting it.
    • B) She must push the string away from herself, because pushing is required to reverse the direction of motion.
    • C) She must push the string toward herself, because any force that slows down an object is classified as a push.
    • D) She must pull the string away from herself, because pulling always acts in the direction an object is already traveling.

Answers and step-by-step solutions appear after you finish the test.