Electric charges come in two forms: positive and negative. What combinations of charges will attract and repel each other?

svlad2 [7]

Answer:

Gravity always attracts. Magnetism either attracts or repel. Gravity reacts to mass or space. Magnetism reacts to motion

4 0

3 years ago

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If the current flowing through an electric heater increases from 6 to 12 amp while the voltage remains the same, the heat produc

Ainat [17]

Q=l^2 times R times t
Where Q - heat, I -current, R - resistance and t is time

If you increase I twice (and it's squared), than Q gonna went up 4 times (2 squared).

Choose last

8 0

4 years ago

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A coffee-cup calorimeter is used to determine the heat of reaction for the reaction of compound A with compound B. A(aq) + B(aq)

Sergeeva-Olga [200]

Answer:

$\rm 1.64\times 10^{3}\; J$ .

Explanation:

Assume that his calorimeter is sufficiently effective, such that no heat had escaped to the surroundings. Heat from this solution would be absorbed by either

the solution, or
the coffee cup.

Temperature change: $33.637 - 23.722 = \rm 9.915\; ^\circ C$ .

<h3>Heat absorbed by the solution:</h3>

Only the specific heat capacity (per unit mass) of the solution is given. Both the mass of the solution and the temperature change will be required for determining the energy change. Start by finding the mass of the solution.

$m = \rho \cdot V = 2\times 16.10 \times 1.00 = \rm 32.10\; g$ .

Calculate the amount of heat absorbed from the specific heat:

$Q = c\cdot m \cdot \Delta T = 4.814\times 32.10 \times 9.915 = \rm 1335.80\; J$ .

<h3>Heat absorbed by the coffee cup:</h3>

The heat capacity of the coffee cup is given. Only the temperature change will be required for finding the amount of heat absorbed.

$Q = C\cdot \Delta T = \rm 30.7\times 9.915 = 304.391\; J$ .

<h3>Heat that this reaction produces</h3>

Find the sum of the two parts of heat. Round to three significant figures as in the heat capacity of the coffee cup and the density of the solution.

$\rm 1335.80+ 304.391 = 1.64\times 10^{3}\; J$ .

8 0

4 years ago

An Astronaut on the Moon drops a rock straight downward from a height of 1.25 meters. If the acceleration of gravity on the Moon

beks73 [17]

Answer:

Since the astronaut drops the rock, the initial velocity of the rock is 0 m/s

<u>We are given:</u>

initial velocity (u) = 0 m/s

final velocity (v) = v m/s

acceleration (a) = 1.62 m/s/s

height (h) = 1.25 m

<u>Solving for v:</u>

From the third equation of motion:

v²-u² = 2ah

replacing the variables

v² - (0)² =2 (1.62)(1.25)

v² = 1.62 * 2.5

v² = 4 (approx)

v = √4

v = 2 m/s

The speed of the rock just before it lands is 2 m/s

8 0

4 years ago

A force acts upon an object causing displacement of the object is the definition of ?

chubhunter [2.5K]

The answer is displacement

3 0

3 years ago