1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
zaharov [31]
3 years ago
9

Which of these factors make hydrogen fuel cells a better option than burning fossil fuels? A.Hydrogen fuel cells have a higher e

nergy efficiency. B.Hydrogen fuel cells create less pollution. C.Burning fossil fuels relies on outdated devices and technology. D.Hydrogen is the most abundant element in the universe. E.Hydrogen fuel cells are more expensive than fossil fuels.
Physics
1 answer:
Pavel [41]3 years ago
3 0

Answer: i think it is B

Explanation:

You might be interested in
A heavy turntable, used for rotating large objects, is a solid cylindrical wheel that can rotate about its central axle with neg
scoundrel [369]

Answer:

a) I = 113.014\,kg\cdot m^{2}, b) m = 2075.556\,kg

Explanation:

a) The turntable has the following physical model by using Newton's laws:

F \cdot R = I \cdot \alpha

The moment of inertia is:

I = \frac{F\cdot R}{\alpha}

I = \frac{(300\,N)\cdot(0.33\,m)}{0.876\,\frac{rad}{s^{2}} }

I = 113.014\,kg\cdot m^{2}

b) The moment of inertia for a solid cylinder:

I = \frac{1}{2}\cdot m \cdot R^{2}

The mass of the turntable is:

m = \frac{2 \cdot I}{R^{2}}

m = \frac{(2)\cdot (113.014\,kg\cdot m^{2})}{(0.33\,m)^{2}}

m = 2075.556\,kg

8 0
3 years ago
Write a hypothesis for Part II of the lab, which is about the relationship described by F = ma. In the lab, you will use a toy c
Tanzania [10]
If you increase the mass m of the car, the force F will increase, while acceleration a is kept constant. Because F and m are directly proportional.
If you increase the acceleration a of the car, the force F will increase, while mass m is kept constant. Because F and a are directly proportional.

How can Newton's laws be verified experimentally; is by setting this experiment, and changing one variable while keeping the other constant, then observe the change in F.

Hope this helps.
5 0
3 years ago
Read 2 more answers
A small drop of water is suspended motionless in air by a uniform electric field that is directed upward and has a magnitude of
uysha [10]

Answer:

q = 4.04×10^-12C

n = 2.53×10^7

Explanation:

1. Electrostatic force on charge due to electrical field E is F = qE

Gravitational force due to weight of drop of mass M is F = mg, when net force is zero we have to find the charges on the drop.

2. Charge on drop: since gravitational force is acting downward, electric field is acting upward and we equate both equations.

Therefore, Fg = Fe

qe = mg

q = mg/E

q = 3.50×10^-9kg×9.8m/s²/8480N/c

q = 4.04 × 10^-12

3. Number of protons by quantitization law

n = q/e

n = 4.04× 10^-12/8480

n = 2.53× 10^7

8 0
3 years ago
How does she explain the activity of uranium when amounts of this element are changed? how does she describe the activity of ura
kifflom [539]

Answer:

What to include in the answer:

Results from edg 2022

Explanation:

Did you include this in your answer?

Chemical compounds are active in direct proportion to the amount of uranium in them.

Activity is not destroyed by physical changes of state or chemical transformations.

Radioactivity is an atomic property of matter.

8 0
2 years ago
A certain laser outputs pure red light (photon energy 1.8 eV) with power 550 milliwatts (0.55 watts). How many photons per secon
Klio2033 [76]

We want to find how many photons per second a laser emits given that we know the energy of a single photon and the power of the laser, we will get:

1.90712*10^18 photons per second.

So we know that the photon energy is 1.8 eV, and the laser power is:

P = 0.55 watts

Remember that:

1 watt = 1 J/s

And:

1 eV = 1.60218*10^(-19) J

Then we can convert the two values that we have so we have both in joules:

Power = P = 0.55 J/s

Energy = 1.8 eV = 1.8*(1.60218*10^(-19) J) = 2.883924*10^(-19) J

The number of photons emitted per second is just the quotient between the power and the energy of a single photon, we have:

Number = (0.55 J/s)/(2.883924*10^(-19) J) = 1.90712*10^18 photons per second.

If you want to learn more, you can read:

brainly.com/question/20343793

5 0
3 years ago
Other questions:
  • Smoking increases ____ levels in the blood, thus increasing the possibility of unwanted clotting.
    14·1 answer
  • If you push for an hour against a stationary wall, you do no work
    8·1 answer
  • Based on the weather station systems shown below, what is the most likely location of the low pressure system?
    8·2 answers
  • What are longitudinal waves?
    11·1 answer
  • Travel north to south how would polaris be situated?
    14·1 answer
  • A car traveling on a level road initially has 440 kJ of mechanical energy. After the brakes are applied for a few seconds, the c
    10·1 answer
  • Describe the sequence of mechanical energy events that lets you hear the
    9·1 answer
  • It takes 50 seconds for Tyler to do 450 Joules of work. How much power did Tyler use?
    9·1 answer
  • Which choice displays the effects of quantum mechanics? check all that apply
    10·1 answer
  • 1.) A neutron in a reactor makes an elastic
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!