The total heat that is needed by the water to get converted to steam is calculated below through the equation,

H = (Hv)(n)

where H is the heat, Hv is the heat of vaporization (40.67 kJ/mol), and n is the number of mols. Substituting the known values,

H = (40.66 kJ/mol)(1.5 mol) = 60.99 kJ

Calculating for the time,

t = (60990 J) / (24 J/s)

t = 2541.25 s

Answer: 2541.25 s or approximately 42.35 minutes

**Explanation:**

Given that, you are taking a picture of a giraffe that is standing far away from you. The image is just too small, so you swap the 60-mm-focal-length lens in your camera for a 960 mm telephoto lens such that,

We need to find the the factor with which the size of the image increases. It can be calculated by taking ratios of both

So,

**So, the size of image increases by a factor of 16. Hence, this is the required solution.**

**Answer:**

the speed of the boat is 21.22ft/min

**Explanation:**

Hello!

To solve this exercise follow the steps below.

1. Draw the complete scheme of the problem (see attached image).

2. As you can see in the image, our goal is to determine the horizontal component of the velocity (Vx) that corresponds to that of the boat, for this the first thing we do is find the alpha angle using the height and the hypotenuse of the triangle.

3. Finally we find the horizontal velocity component using the cosine function

the speed of the boat is 21.22ft/min

<h2>

**Answer: Both objects have charges of the same sign**</h2>

When two electrically charged bodies come closer, appears a force that attracts or repels them, depending on the sign of the charges of this two bodies.

This is stated by **Coulomb's Law:**

"The **electrostatic force** between **two point charges ** and is proportional to the product of the charges and inversely proportional to the square of the **distance** that separates them, and has the direction of the line that joins them"

Mathematically this law is written as:

Where is a **proportionality constant.
**

Now, if and have the same sign charge (both positive or both negative), a repulsive force will act on these charges.

**Answer:**

The correct answers to the question are

1. Environmental variable c,

2. Input variable a,

3. Output variable b,

4. Input variable a,

5. Input variable a,

6. Input variable a

**Explanation:**

1. Outside temperature.

This is is an environmental variable regarding where the observation is taking place

2. Duration that the soup was heated before being put in the bowl.

This can be controlled so it is an input variable

3. Temperature of the soup in a student's bowl.

This depends on the initial temperature the soup was heated to so it is an output variable

4. Temperature level to which the soup is warmed up.

Input variable as it can be controlled o varied

5. Insulation of the bowl used for storing the soup.

This is an input variable as the type of bowl can be selected

6. Duration that the soup bowl is open when the server inserts the ladle to serve a student.

server or the operator of the cafeteria