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3 years ago

At $0.095/kwh, what does it cost to leave a 25 w porch light on day and night for a year?

Physics

1 answer:

Veronika [31]3 years ago

3 0

Answer:

It will cost $20.81

Explanation:

Cost of Electricity

The rate of the cost of electricity is usually expressed in $/KWH because the consumption of electricity is measured in Kilowatts-hour.

If a 25W porch light is on day and night for a full year, the electricity consumption is:

25W*24 H/Day*365 Day/year* 1 year=219,000 WH

converting to KWH: 219,000 WH = 219,000 /1000 KWH = 219 KWH

The rate is $0.095/KWH, thus:

The cost of electricity is 219 KWH*$0.095/KWH= $20.81

It will cost $20.81

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What is the acceleration of a 3 kilogram object if a force of 36 Newtons is applied to it

FromTheMoon [43]

Force = Mass x Acceleration -> Acceleration = Force/Mass:
36N/3kg = 12 m/s^2

4 0

4 years ago

If you have 240.0 mL of water at 25.00 °C and add 100.0 mL of water at 95.00 °C, what is the final temperature of the mixture? U

Rus_ich [418]

Answer: The final temperature of the mixture is 45.6°C

Explanation:

To calculate the mass of water, we use the equation:

$\text{Density of substance}=\frac{\text{Mass of substance}}{\text{Volume of substance}}$

Density of water = 1 g/mL

When volume is 240.0 mL

Putting values in above equation, we get:

$1g/mL=\frac{\text{Mass of water}}{240.0mL}\\\\\text{Mass of water}=(1g/mL\times 240.0mL)=240g$

When volume is 100.0 mL

Putting values in above equation, we get:

$1g/mL=\frac{\text{Mass of water}}{100.0mL}\\\\\text{Mass of water}=(1g/mL\times 100.0mL)=100g$

When two water solutions at different temperature are mixed, the amount of heat released by water present at higher temperature will be equal to the amount of heat absorbed by water present at lower temperature..

$Heat_{\text{absorbed}}=Heat_{\text{released}}$

The equation used to calculate heat released or absorbed follows:

$Q=m\times c\times \Delta T=m\times c\times (T_{final}-T_{initial})$

$m_1\times c\times (T_{final}-T_1)=-[m_2\times c\times (T_{final}-T_2)]$ ......(1)

where,

q = heat absorbed or released

$m_1$ = mass of water solution 1 = 240 g

$m_2$ = mass of water solution 2 = 100 g

$T_{final}$ = final temperature = ?°C

$T_1$ = initial temperature of water solution 1 = 25°C

$T_2$ = initial temperature of water solution 2 = 95°C

c = specific heat of water= 4.186 J/g°C

Putting values in equation 1, we get:

$240\times 4.186\times (T_{final}-25)=-[100\times 4.186\times (T_{final}-95)]\\\\T_{final}=45.6^oC$

Hence, the final temperature of the mixture is 45.6°C

7 0

3 years ago

Read 2 more answers

A gymnast is in a tucked position to complete her somersaults. While tucked her moment of inertia about an axis through the cent

torisob [31]

Answer:

$\omega_s=12.8886\ rad.s^{-1}$

Explanation:

Given that:

moment of inertia of tucked body, $I_t=16\ kg.m^2$

rotational speed of the body, $N_t=2.5\ rev.s^{-1}$

i.e. $\omega_t=2\pi\times 2.5=15.708\ rad.s^{-1}$

moment of inertia of the straightened body, $I_s=19.5\ kg.m^2$

Now using the law of conservation of angular momentum:

angular momentum of tucked body=angular momentum of straight body

$I_t.\omega_t=I_s.\omega_s$

$16\times 15.708=19.5\times \omega_s$

$\omega_s=12.8886\ rad.s^{-1}$

8 0

3 years ago

What is a supernova type ia

solmaris [256]

It is a supernova that is thought to be a result of a explosion of a carbon-oxygen white dwarf in a binary system.

7 0

4 years ago

WILL GIVE BRAINLIEST!!!

kumpel [21]

Answer:

72.53 mi/hr

Explanation:

From the question given above, the following data were obtained:

Vertical distance i.e Height (h) = 8.26 m

Horizontal distance (s) = 42.1 m

Horizontal velocity (u) =?

Next, we shall determine the time taken for the car to get to the ground.

This can be obtained as follow:

Height (h) = 8.26 m

Acceleration due to gravity (g) = 9.8 m/s²

Time (t) =?

h = ½gt²

8.26 = ½ × 9.8 × t²

8.26 = 4.9 × t²

Divide both side by 4.9

t² = 8.26 / 4.9

Take the square root of both side by

t = √(8.26 / 4.9)

t = 1.3 s

Next, we shall determine the horizontal velocity of the car. This can be obtained as follow:

Horizontal distance (s) = 42.1 m

Time (t) = 1.3 s

Horizontal velocity (u) =?

s = ut

42.1 = u × 1.3

Divide both side by 1.3

u = 42.1 / 1.3

u = 32.38 m/s

Finally, we shall convert 32.38 m/s to miles per hour (mi/hr). This can be obtained as follow:

1 m/s = 2.24 mi/hr

Therefore,

32.38 m/s = 32.38 m/s × 2.24 mi/hr / 1 m/s

32.38 m/s = 72.53 mi/hr

Thus, the car was moving at a speed of

72.53 mi/hr.

7 0

3 years ago