Javier made a list about balanced and unbalanced forces.
Balanced Forces Unbalanced Forces
can cause an object to speed up, slow down, or change directions
cause objects to stay in the same place or to continue moving at the same speed
Javier made a mistake on his list. Which best describes the mistake Javier made?
A.
Javier forgot to add that forces can never change.
B.
Balanced forces only cause objects to change directions.
C.
Unbalanced forces only cause objects to stay in the same place.
D.
Javier switched the descriptions for unbalanced and balanced forces.
11 answers
The best description of the mistake Javier made is:
D. Javier switched the descriptions for unbalanced and balanced forces.
Balanced forces do cause objects to stay in the same place or to continue moving at the same speed, while unbalanced forces can cause an object to speed up, slow down, or change directions.
The best answer to the question of why the disk falls straight down into the glass when the index card is quickly pulled away is:
D. inertia.
Inertia is the tendency of an object to remain in its state of motion. When the index card is pulled away quickly, the disk has inertia that keeps it moving downward due to gravity, causing it to fall straight down into the glass instead of moving horizontally with the card.
The argument that best supports the student's claim that box 1 must have a smaller mass than box 2 is:
B. Heavier objects require greater force than lighter objects to accelerate at the same rate.
Since both boxes have the same applied force (20 newtons) but box 1 has a greater acceleration (5 meters/second²) compared to box 2 (2 meters/second²), it indicates that box 1 is lighter, as it accelerates more with the same force. This aligns with the principle that greater mass requires greater force to achieve the same acceleration.
The argument that best supports the student's claim that a field exists between the rod and the magnet is:
A. The current in the wire has created a magnetic field with its north pole at the top of the rod.
When a current flows through a wire, it generates a magnetic field. If the north pole of the bar magnet is experiencing a force pushing it away from the rod, it indicates that the magnetic field created by the current-carrying wire is interacting with the magnetic field of the magnet. Therefore, there is a magnetic field present in the space between the rod and the magnet.
The argument that best supports the student's claim that the gravitational force is greater between the objects in Figure A is:
C. The distance between the objects in Figure A is shorter than the distance between the objects in Figure B.
According to the law of universal gravitation, the gravitational force between two objects increases as the mass of the objects increases but decreases as the distance between them increases. If the objects in Figure A are closer together than those in Figure B, this would support the student’s claim that the gravitational force is greater in Figure A.
The statement that best predicts what will happen to the charge on the hollow, neutral metal sphere after touching it with the negatively charged rubber rod is:
C. It will distribute itself evenly over the surface of the sphere, because like charges repel and the sphere is a conductor.
When the negatively charged rod comes into contact with the metal sphere, the excess negative charge will spread out evenly over the surface of the conductor due to the repulsive forces between the like charges. Conductors allow free movement of charges, leading to an even distribution.
