A bowling ball is moving down a flat bowling lane at a constant speed. Which statements best describe the movement of this bowling ball? Select all that apply.

Question

A.
Its movement is caused by unbalanced forces.

B.
Its movement changes without a force acting upon it.

C.
Its movement shows Newton's first law of motion.

D.
Its movement shows Newton's third law of motion.

E.
Its movement shows Newton's second law of motion.

F.
Its movement remains the same unless a force acts upon it.

Answer 1

The statements that best describe the movement of the bowling ball, which is moving down a flat bowling lane at a constant speed, are:

C. Its movement shows Newton's first law of motion. F. Its movement remains the same unless a force acts upon it.

Here's the reasoning:

• Option A: Incorrect. The bowling ball is moving at a constant speed, which implies that there are no unbalanced forces acting on it.
• Option B: Incorrect. The bowling ball's movement does not change because it is moving at a constant speed.
• Option C: Correct. Newton's first law states that an object in motion will stay in motion at a constant velocity unless acted upon by an unbalanced force.
• Option D: Incorrect. Newton's third law pertains to action-reaction pairs and does not directly describe the constant motion of the ball.
• Option E: Incorrect. Newton's second law relates to the acceleration of an object (F = ma), which is not applicable here since the ball is moving at a constant speed (zero acceleration).
• Option F: Correct. This is a restatement of Newton's first law in practical terms, indicating that the bowling ball will continue in its state of motion unless acted upon by a force.

Thus, the correct options are C and F.

Answer 2

A student built a simple electromagnet with copper wire, an iron bolt, and a 1.5-volt battery. The electromagnet was able to lift a paper clip from 3 centimeters away. Select three ways the student can increase the strength of his electromagnet.

A.
He can use a thicker piece of copper wire.

B.
He can reverse the orientation of the battery.

C.
He can replace the iron bolt with a wooden rod.

D.
He can add a switch between the battery and the iron bolt.

E.
He can replace the 1.5-volt battery with a battery of higher voltage.

F.
He can use a longer piece of wire that wraps more times around the bolt.

Answer 3

To increase the strength of the student's electromagnet, the following three options can be selected:

E. He can replace the 1.5-volt battery with a battery of higher voltage.

• Increasing the voltage provides more current to the wire, which can strengthen the magnetic field.

F. He can use a longer piece of wire that wraps more times around the bolt.

• More turns of wire around the iron core increase the electromagnetic field strength because the magnetic field strength is proportional to the number of turns in the coil.

A. He can use a thicker piece of copper wire.

• While using a thicker wire could lower the resistance and allow more current to flow, which might contribute to a stronger magnetic field, this is a less direct method compared to increasing the voltage or adding more turns.

Summary: The best three answers specifically focusing on significantly increasing the strength of the electromagnet are E, F, and A.

Option B (reversing the battery) does not increase strength; it simply changes the direction of the magnetic field.
Option C (using a wooden rod) is incorrect, as wood is not ferromagnetic and would not enhance the magnetic effect.
Option D (adding a switch) does not improve the strength of the magnet itself but merely allows for control over when it is on or off.