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3 years ago

If a chemical reaction has a AH value of -125 kJ, it would be considered what?

Physics

2 answers:

egoroff_w [7]3 years ago

4 0

exothermic

Explanation:

negative means it's losing energy

Gnom [1K]3 years ago

3 0

A an exothermic reaction

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if a gas has a gage pressure of 156 kpa its absolute pressure is approximately .....A... 56 kPa ....B....100 kPa.......C......25

NeX [460]

256 kPa because p-guage + p-absolute + p-atmospheric = 256

7 0

4 years ago

A radio wave has a frequency of 5.5 × 104 hertz and travels at a speed of 3.0 × 108 meters/second. What is its wavelength

Ne4ueva [31]

Use v=fλ
3x10^8=5.5x 10^4 λ
λ=5.45x10^3m

4 0

3 years ago

Read 2 more answers

Which is not an example of a scalar?

Crank

Answer:

b) 2ft/s

Explanation:

A scalar has only magintude, not direction

6.2m, 3kg, and -100 o C are all scalars because they only have magnitude.

2ft/s is not a scalar because it has a direction.

3 0

2 years ago

Gwen is researching the effects of a small asteroid impact in an area that has started to regrow after being hit ten years ago.

Bumek [7]

Answer:

Gwen’s assumption of asteroid hit as long term change is incorrect. Asteroid hit is not a long term change, instead, it is a short term change.

Explanation:

Examples of short term changes are drought, flood, volcanic eruption, etc. A short term change occurs quickly and can immediately affect organisms but it doesn’t become a reason for species extinction. The effects of a short term change don’t prevail over a long span of time.

Examples of long term changes are ice age, global warming, deforestation, etc. Unlike a short term change, it takes time but the consequences are far-reaching. It can lead to species extinction.

In this question, asteroid hit is a quick and unexpected hazard, unlike the slow long term environmental changes.

3 0

3 years ago

Read 2 more answers

Aconstant current of 3 Afor 4 hours is required to charge an automotive battery. If the terminal voltage is V, where t is in hou

kirza4 [7]

Answer:

(a) 43.2 kC

(b) 0.012V kWh

(c) 0.108V cents

Explanation:

<u>Given:</u>

i = current flow = 3 A
t = time interval for which the current flow = $4\ h = 4\times 3600\ s = 14400\ s$
V = terminal voltage of the battery
R = rate of energy = 9 cents/kWh

<u>Assume:</u>

Q = charge transported as a result of charging
E = energy expended
C = cost of charging

Part (a):

We know that the charge flow rate is the electric current flow through a wire.

$\therefore i = \dfrac{Q}{t}\\\Rightarrow Q =it\\\Rightarrow Q = 3\times 14400\\\Rightarrow Q = 43200\ C\\\Rightarrow Q = 43.200\ kC\\$

Hence, 43.2 kC of charge is transported as a result of charging.

Part (b):

We know the electrical energy dissipated due to current flow across a voltage drop for a time interval is given by:

$E = Vit\\\Rightarrow E = V\times 3\times 4\\\Rightarrow E = 12V\ Wh\\\Rightarrow E = 0.012V\ kWh\\$

Hence, 0.012V kWh is expended in charging the battery.

Part (c):

We know that the energy cost is equal to the product of energy expended and the rate of energy.

$\therefore \textrm{Cost}=\textrm{Energy}\times \textrm{Rate}\\\Rightarrow C = ER\\\Rightarrow C = 0.012V\times 9\\\Rightarrow C =0.108V\ cents$

Hence, 0.108V cents is the charging cost of the battery.

4 0

4 years ago