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2 years ago

20 POINTS What is an endothermic reaction?

Physics

2 answers:

Ratling [72]2 years ago

7 0

Answer:

An endothermic reaction is a chemical reaction in which more energy is needed to break bonds in the reactants than is released when new bonds form in the products.

A constant input of energy, often in the form of heat, is needed to keep an endothermic reaction going.

Explanation:

A would be the answer

tiny-mole [99]2 years ago

3 0

Answer:

A reaction that contributes energy to the surroundings

Explanation:

When energy is taken in from the Surroundings, the temperature of the surroundings decreases

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What two factors determine the density of a fluid?

tekilochka [14]

Answer:

Mass and volume.

Explanation:

The equation for density is always mass divided by volume. To determine the density of a fluid, you would need to find its volume and its mass.

6 0

3 years ago

Below is a circuit schematic of sources and resistors (Figure 3). VS = 10V , R1 = 100Ω, R2 = 50Ω, R3 = 25Ω, IS = 2A. Calculate t

lorasvet [3.4K]

Answer:

$V_3\approx 4.28\,\,V$

$I_1=0.0572\,\,amps$

$I_3\approx 0.171\,\,amps$

Explanation:

Notice that this is a circuit with resistors R1 and R2 in parallel, connected to resistor R3 in series. It is what is called a parallel-series combination.

So we first find the equivalent resistance for the two resistors in parallel:

$\frac{1}{Re}= \frac{1}{R1}+\frac{1}{R2}\\\frac{1}{Re}= \frac{1}{100}+\frac{1}{50}\\\frac{1}{Re}= \frac{3}{100}\\Re=\frac{100}{3} \,\,\Omega$

By knowing this, we can estimate the total current through the circuit,:

$Vs=I\,*\,(\frac{100}{3} +25)\\10=I\,*\,\frac{175}{3} \\I=\frac{30}{175} \,amps$

So approximately 0.17 amps

and therefore, we can estimate the voltage drop (V3) in R3 uisng Ohm's law:

$V_3=\frac{30}{175} *\,25=\frac{30}{7} \approx 4.28\,\,V$

So now we know that the potential drop across the parellel resistors must be:

10 V - 4.28 V = 5.72 V

and with this info, we can calculate the current through R1 using Ohm's Law:

$I_1=\frac{V_1}{R_1} =\frac{5.72}{100} =0.0572\,\,amps$

4 0

3 years ago

Someone drops a brick on a 2.6 kg cart moving at 28.2 cm/s. After the collision, the dropped brick and cart are moving together

Softa [21]

Answer:

2.087 kg

Explanation:

From the law of conservation of momentum,

Total momentum before collision = total momentum after collision.

MU + mu = V(M+m)............................ Equation 1

Where M = mass of the cart, m = mass of the brick, U = initial velocity of the cart, u = initial velocity of the brick, V = velocity of both cart and brick after collision.

Note: The initial velocity of the brick is zero Thus mu = 0

making m the subject of the equation,

m =(MU/V)-M ........................................ Equation 2

Given: M = 2.6 kg, U = 28.2 cm/s = 0.283 m/s, V = 15.7 cm/s = 0.157 m/s.

Substituting into equation 2,

m = (2.6×0.283/0.157)-2.6

m = 2.087 kg

Thus the mass of the brick = 2.087 kg

5 0

3 years ago

Which situation is most likely to lead to improving a scientific theory?

Nonamiya [84]

Answer:

A. Repeating an experiment to verify results

Explanation:

A scientific theory may be defined as the theory of science that is a thought out explanation of the observations done in the nature or that happens in the natural world. They are constructed using several scientific methods by observing many facts and hypothesis.

According to the question, repeating of an experiment a number of times and verifying its result may help in improving a scientific theory as if we get the similar result for each experiments, then it confirms the basis of the hypothesis or the facts that are observe in the nature and conclude a scientific theory.

4 0

3 years ago

Please HELP! Many points! How much work does a weightlifter do if he lifts a 400 Newton barbell 3 meters high- 15 times???

77julia77 [94]

Work = (force) x (distance)

1 time: (400 newtons) x (3 meters) = 1,200 joules

15 times: (1,200 joules) x (15) = 18,000 joules

4 0

3 years ago

20 POINTS What is an endothermic reaction?​

20 POINTS What is an endothermic reaction?