Exam 8 Numbers 6-10 PreAP

1. 6. Electric force and gravitational force are alike in that both forces

A. depend on charge.

B. act only when objects are touching.

C. depend on mass.

D. are field forces.

Electric force and gravitational force are both field forces because they act on objects even when they are not in direct contact with each other. Electric force is the force between charged particles, while gravitational force is the force between objects with mass. Both forces can act over a distance and do not require physical contact between the objects. Therefore, the correct answer is d. are field forces.

Explanation

Electric force and gravitational force are both field forces because they act on objects even when they are not in direct contact with each other. Electric force is the force between charged particles, while gravitational force is the force between objects with mass. Both forces can act over a distance and do not require physical contact between the objects. Therefore, the correct answer is d. are field forces.

2. 7. Which of the following best represents a difference between electric force and gravitational force?

A. Gravitational force is stronger than electric force.

B. Electric force can both attract and repel.

C. Electric force is inversely proportional to the square of the distance between objects.

D. Gravitational force exists between objects that are not touching.

The correct answer is b. Electric force can both attract and repel. This is because electric force is caused by the interaction of charged particles, which can have positive or negative charges. Like charges repel each other, while opposite charges attract each other. In contrast, gravitational force only attracts objects and does not have the ability to repel.

Explanation

The correct answer is b. Electric force can both attract and repel. This is because electric force is caused by the interaction of charged particles, which can have positive or negative charges. Like charges repel each other, while opposite charges attract each other. In contrast, gravitational force only attracts objects and does not have the ability to repel.

3. 9. Two 1 kg spheres each carry a charge of magnitude 1 C. How does F_E, the strength of the electric force between the spheres, compare with F_G, the strength of their gravitational attraction?

A. FE < FG

B. FE = FG

C. FE > FG

E. Cannot be determined without knowing the distance between the spheres

The electric force between the spheres, FE, is greater than the gravitational attraction, FG. This is because the electric force is determined by the magnitude of the charges and the distance between them, while the gravitational attraction is determined by the masses of the spheres and the distance between them. Since the charges on the spheres are the same and the masses are equal, the electric force will be greater than the gravitational attraction.

Explanation

The electric force between the spheres, FE, is greater than the gravitational attraction, FG. This is because the electric force is determined by the magnitude of the charges and the distance between them, while the gravitational attraction is determined by the masses of the spheres and the distance between them. Since the charges on the spheres are the same and the masses are equal, the electric force will be greater than the gravitational attraction.

4. 8. Which of the following is not true for both gravitational and electric forces?

A. The inverse square distance law applies.

B. Forces are proportional to physical properties.

C. Potential energy is a function of distance of separation.

D. Forces are either attractive or repulsive.

Both gravitational and electric forces are always either attractive or repulsive. Gravitational forces are always attractive, meaning they pull objects towards each other. Electric forces can be either attractive or repulsive, depending on the charges of the objects involved. Like charges repel each other, while opposite charges attract each other. Therefore, the statement that forces are either attractive or repulsive is true for both gravitational and electric forces.

Explanation

Both gravitational and electric forces are always either attractive or repulsive. Gravitational forces are always attractive, meaning they pull objects towards each other. Electric forces can be either attractive or repulsive, depending on the charges of the objects involved. Like charges repel each other, while opposite charges attract each other. Therefore, the statement that forces are either attractive or repulsive is true for both gravitational and electric forces.

5. 10. When comparing the force of attraction between an electron and a proton due to the electric force and gravity, it can be concluded that

A. the gravitational force is a lot stronger

B. the electric force is a lot stronger

C. the two types of forces are the same

D. they cannot be compared

E. the electric force is slightly stronger

The correct answer is b. the electric force is a lot stronger. This is because the electric force between an electron and a proton is much stronger than the gravitational force between them. The electric force is determined by the charges of the particles, while the gravitational force is determined by their masses. Since the charge of an electron is much larger than its mass, the electric force dominates over gravity in this scenario.

Explanation

The correct answer is b. the electric force is a lot stronger. This is because the electric force between an electron and a proton is much stronger than the gravitational force between them. The electric force is determined by the charges of the particles, while the gravitational force is determined by their masses. Since the charge of an electron is much larger than its mass, the electric force dominates over gravity in this scenario.

Exam 8 Numbers 6-10 Preap