Question

The mechanical advantage of a wheel and axle is the radius of the wheel divided by the radius of the axle.

What is the mechanical advantage of the wheel and axle shown below?

15cm 2.5cm

(1 point)
Responses

0.17
0.17

6
6

37.5
37.5

17.5
17.5

12.5


If the distance between two objects is doubled, what happens to the gravitational force between them?(1 point)
Responses

it doubles
it doubles

it decreases to 1/2 of its original value
it decreases to 1/2 of its original value

it stays the same
it stays the same

it decreases to 1/4 of its original value


The surface of a heated metal object measures 120°C. It is dropped into a bucket filled with water measuring 10°C.

Which of the following is most likely to occur?

(1 point)
Responses

The water and metal will adjust to the same temperature between 10°C and 120°C.
The water and metal will adjust to the same temperature between 10°C and 120°C.

The water will remain the same temperature, but the metal will cool to 10°C
The water will remain the same temperature, but the metal will cool to 10°C

Both the water and metal will adjust to the same temperature below 10°C.
Both the water and metal will adjust to the same temperature below 10°C.

The water and metal will adjust to different temperatures above 120°C.


Which of the following directly affects the strength of an electromagnet?(1 point)
Responses

Length of core, type of force
Length of core, type of force

Number of coils, amount of current
Number of coils, amount of current

Type of force, number of coils
Type of force, number of coils

Amount of current, type of force


What is the energy conversion that happens inside a battery?(1 point)
Responses

Heat Energy to Potential Energy
Heat Energy to Potential Energy

Kinetic Energy to Potential Energy
Kinetic Energy to Potential Energy

Electrical Energy to Kinetic Energy
Electrical Energy to Kinetic Energy

Chemical Energy to Electrical Energy


Using Coulomb's Law, if the size of one of the charges increases (and the distance remains the same), what happens to the electric force between them?



(1 point)
Responses

Electrostatic force will increase.
Electrostatic force will increase.

Electrostatic force will decrease.
Electrostatic force will decrease.

Electrostatic force will reverse direction.
Electrostatic force will reverse direction.

Electrostatic force will remain the same.
Electrostatic force will remain the same.

Answers

GPT-4o mini
Here are the answers to each of your questions:

1. **Mechanical Advantage of the Wheel and Axle:**
- The formula for mechanical advantage (MA) of a wheel and axle is given by \( \text{MA} = \frac{r_{\text{wheel}}}{r_{\text{axle}}} \).
- Given \( r_{\text{wheel}} = 15 \, \text{cm} \) and \( r_{\text{axle}} = 2.5 \, \text{cm} \):
\[
\text{MA} = \frac{15}{2.5} = 6
\]
- **Answer: 6**

2. **Effect of Doubling Distance on Gravitational Force:**
- According to the law of universal gravitation, the gravitational force \( F \) is inversely proportional to the square of the distance \( r \) between two objects: \( F \propto \frac{1}{r^2} \).
- If the distance is doubled (\( r \to 2r \)):
\[
F' = \frac{G m_1 m_2}{(2r)^2} = \frac{G m_1 m_2}{4r^2} = \frac{1}{4} F
\]
- **Answer: it decreases to 1/4 of its original value**

3. **Temperature Change After Metal is Dropped in Water:**
- When a heated metal object is placed in cooler water, heat will transfer from the metal to the water until they reach thermal equilibrium.
- The final temperature will be between 10°C and 120°C.
- **Answer: The water and metal will adjust to the same temperature between 10°C and 120°C.**

4. **Factors that Affect the Strength of an Electromagnet:**
- The strength of an electromagnet is influenced by the number of coils of wire around the core and the amount of electric current passing through those coils.
- **Answer: Number of coils, amount of current**

5. **Energy Conversion Inside a Battery:**
- Inside a battery, chemical energy is converted into electrical energy as a result of chemical reactions.
- **Answer: Chemical Energy to Electrical Energy**

6. **Effect of Increasing the Size of Charges on Electric Force (Coulomb's Law):**
- According to Coulomb's Law, the electric force \( F \) is directly proportional to the product of the magnitudes of the charges \( q_1 \) and \( q_2 \): \( F \propto \frac{q_1 q_2}{r^2} \).
- If one of the charges increases while the distance remains the same, the electric force will increase.
- **Answer: Electrostatic force will increase.**

Let me know if you need further assistance!