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dalvyx [7]
4 years ago
9

A garage door opener has a power rating of 350 watts. If the door is in operation for 30 seconds, how many joules of energy are

used? (Hint: Remember that 1 watt = 1 joule/sec)
Physics
1 answer:
Novosadov [1.4K]4 years ago
8 0
Because of the hint we can conclude what equation we need to solve this problem. We have power and duration that means that we need to express energy:

1 joule = 1watt * 1 second
or
E (energy) = P (power) * t (time duration)
E = 350 * 30 = 10500 joules.
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PLZ HELP ME The stored energy in organic matter or wastes is called biomass energy and when burned can be used to produce therma
Softa [21]

Answer:  

True: The stored energy in organic matter or wastes is called biomass energy and when burned can be used to produce thermal energy used for cooking, heating homes or generating electricity.

Explanation:

For Household Needs, biomass is utilized for home heating or for cooking purposes. In that case the most common source for fuel is wood, but there are also other substances are used. Latest wood-stoves designs are made in an effective way for heating and cooking needs. With the help of those new technologies fuel consumption is decreased to a significant amount.

Humans have been using biomass energy since ages for cooking their food and heating homes by burning woods. Biomass energy can be used in homes for heating or cooking or in industries large power plants to produce electricity

What is Biomass Energy? Biomass consists of energy in stored form taken from the sun. In photosynthesis plants take energy from sun. By burning biomass the energy emitted in result can be used for heating purposes. There are many types of biomass energy made by either burning or by converting it into liquids or gas, called Bio-fuels and Bio-gas.    

Summary:

No doubt Biomass contribute in air pollution formation but it is less than the pollution caused by certain gases and fossils fuels which produce sulfur resulting in acidic rain and polluting our environment.    

3 0
4 years ago
A singly ionized helium atom is in the ground state. It absorbs energy and makes a transition to the n = 3 excited state. The io
IRISSAK [1]

Answer:

\lambda=25.6nm

Explanation:

The Rydberg formula can be extended for use with any hydrogen-like chemical elements, that is to say with only one electron being affected by effective nuclear charge. So, in this case, we can calculate the wavelenghts of the emitted photons using this formula:

\frac{1}{\lambda}=RZ^2(\frac{1}{n_1^2}-\frac{1}{n_2^2})

Where R is the Rydberg constant of the element, Z its atomic number, n_1 is the lower energy level and n_2 the upper energy level of the  electron transition. Recall that the ground state is denoted as n=1.

\frac{1}{\lambda}=1.1*10^7m^{-1}(2)2^2(\frac{1}{1^2}-\frac{1}{3^2})\\\frac{1}{\lambda}=3.91*10^7m^{-1}\\\lambda=2.56*10^{-8}m=25.6nm

7 0
3 years ago
The free-fall acceleration on Mars is 3.7 m/s2.
hichkok12 [17]

Answer:

(a) The length of the pendulum on Earth is 36.8cm

(b) The length of the pendulum on Mars is 13.5cm

(c) Mass suspended from the spring on Earth is 0.37kg

(d) Mass suspended from the spring on Mars is 0.36kg

Explanation:

Period = 1.2s, free fall acceleration on Earth = 9.8m/s^2, free fall acceleration on Mars = 3.7m/s^2

( a) Length of pendulum on Earth = [( period ÷ 2π)^2] × acceleration = (1.2 ÷ 2×3.142)^2 × 9.8 = 0.0365×9.8 = 0.358m = 35.8cm

(b) Length of the pendulum on Mars = (1.2÷2×3.142)^2 × 3.7 = 0.0365×3.7 = 0.135cm = 13.5m

(c) Mass suspended from the spring on Earth = (force constant×length in meter) ÷ acceleration = (10×0.358) ÷ 9.8 = 0.37kg

(d) Mass suspended from the spring on Mars = (10×0.135)÷3.7 = 0.36kg

6 0
3 years ago
A volumetric flask made of Pyrex is calibrated at 20.0°C. It is filled to the 150-mL mark with 34.5°C acetone. After the flask i
8_murik_8 [283]

Answer:149.73 ml

Explanation:

Given

\beta \ of\ acetone=1.50\times 10^{-4} ^{\circ}C^{-1}

change in volume is given by

\Delta V=V_{final}-V_{initial}

\Delta V=\nu_{initial}\beta _{acetone}\left [ T_f-T_i\right ]

V_{final}=\nu_{initial}+\nu_{initial}\beta _{acetone}\left [ T_f-T_i\right ]

V_{final}=150+150\times 1.50\times 10^{-4}\left [ 20-32\right ]

V_{final}=149.73 ml

3 0
3 years ago
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olga_2 [115]

Answer:

that it is bumpy or by the sun

Explanation:

4 0
3 years ago
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