Which of these factors make hydrogen fuel cells a better option than burning fossil fuels?
-Hydrogen fuel cells have a higher energy efficiency.
-Hydrogen fuel cells create less pollution.
-Burning fossil fuels relies on outdated devices and technology.
-Hydrogen is the most abundant element in the universe.
-Hydrogen fuel cells are more expensive than fossil fuels.

Answer:

2000g

Explanation:

volume=mass/density

=2000/2.5

=800cm³

mass=density×volume

=800×2.5

=2000g

I hope this helps you ^-^

Complete Question:

What is the power in a circuit that has a current of 12 amps and a resistance of 100 ohms?

Answer:

D. 14,400 watts

Explanation:

The electrical power of an electric circuit can be defined as a measure of the rate at which energy is either produced or absorbed in the circuit.

Mathematically, electrical power is given by the formula;

[tex] Electrical \; power = current * voltage [/tex]

This ultimately implies that, the quantity (current times voltage ) is electrical power and it is measured (S.I units) in Watt (W).

Given the following data;

To find the power in the circuit, we would use the following formula;

Power = I²R

Where;

Power = 12² * 100

Power = 144 * 100

Power = 144,000 Watts

Answer:

Gravitational potential

Explanation:

Any object that is not on the surface of the Earth, but at a height instead has potential energy. Eventually, this can become kinetic energy once the object falls.

When an object is in a gravitational field, it has energy in its gravitational potential energy store.

Answer:

a is your answer.............

Answer:

Explanation:

Use the kinematic equation.

This equation can be derived from [tex]f=ma[/tex], but we can just memorize, or look them up when needed as it saves us time.

Now we can plug our measurements into each variable to solve for acceleration.

Subtract 8m/s from both sides.

Divide by 5 seconds. Left with acceleration in terms of [tex]\frac{m}{s^2}[/tex]

Answer:

1270 segundos

Explanation:

Dada,

Velocidad ( v ) = 3810 m/s

Distancia ( s ) = 3 m

Encontrar : -

Tiempo que tarda el sonido en viajar ( t ) = ?

Fórmula : -

s = d / t

t = d / s

= 3810 / 3

t = 1270 segundos

Answer:

9.75 x 10^4 J

Explanation:

Work done, W = 9.75 x 10^4 J

According to the work energy theorem, the change in kinetic energy is equal to the work done by all the forces.

So, here work done is 9.75 x 10^4 J so the change in kinetic energy is 9.75 x 10^4 J.

Answer:

La longitud de la varilla de cobre es de 1.201 metros a una temperatura de 100 °C.

Explanation:

Asumiendo que la varilla de cobre experimenta deformaciones muy pequeñas y que las deformaciones no longitudinales son despreciables con respecto a las deformaciones longitudinales, la deformación longitudinal de la varilla se estima mediante la siguiente fórmula:

[tex]l_{f} = l_{o}\cdot [1+\alpha \cdot (T_{f}-T_{o})][/tex] (1)

Donde:

[tex]l_{o}[/tex] - Longitud inicial de la varilla, en metros.

[tex]\alpha[/tex] - Coeficiente de dilatación, en [tex]^{\circ}C^{-1}[/tex].

[tex]T_{o}[/tex] - Temperatura inicial de la varilla, en grados Celsius.

[tex]T_{f}[/tex] - Temperatura final de la varilla, en grados Celsius.

Si sabemos que [tex]l_{o} = 1.20\,m[/tex], [tex]\alpha = 1.4\times 10^{-5}\,^{\circ}C^{-1}[/tex], [tex]T_{o} = 18\,^{\circ}C[/tex] y [tex]T_{f} = 100\,^{\circ}C[/tex], entonces la longitud final de la varilla es:

[tex]l_{f} = (1.20\,m)\cdot \left[1 + \left(1.4\times 10^{-5}\,^{\circ}C^{-1}\right)\cdot (100\,^{\circ}C-18\,^{\circ}C)\right][/tex]

[tex]l_{f} = 1.201\,m[/tex]

La longitud de la varilla de cobre es de 1.201 metros a una temperatura de 100 °C.

Answer:

4 m

Explanation:

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

Initial velocity (u) = 10 m/s

Acceleration (a) = –8m/s²

Time (t) = 2 s

Displacement (s) =?

The displacement of the object can be obtained as follow:

s = ut + ½at²

s = (10 × 2) + (½ × –8 × 2²)

s = 20 + (–4 × 4)

s = 20 + (–16)

s = 20 – 16

s = 4 m

Thus, the displacement of the object is 4 m.

Answer:

-4500 N

Source: Brainly

The police officer must be angry 0_0

Answer:

Write any three differences between single fixed pulley and single moveable pulley.

Single fixed pulley;

Single moved pulley;

Complete Question

A light spring with force constant 3.05 N/m is compressed by 7.80 cm as it is held between a 0.400-kg block on the left and a 0.800-kg block on the right, both resting on a horizontal surface. The spring exerts a force on each block, tending to push the blocks apart. The blocks are simultaneously released from rest. Find the acceleration with which each block starts to move, given that the coefficient of kinetic friction between each block and the surface is 0, 0.035, and 0.397. (Let the coordinate system be positive to the right and negative to the left. Indicate the direction with the sign of your answer. Assume that the coefficient of static friction is the same as the coefficient of kinetic friction. If the block does not move, enter 0.)

(a) u = 0 heavier block m/s2 m/s2 lighter block

(b)M = 0.035 heavier block m/s2 m/s2 lighter block

Answer:

a)  [tex]A_h=0.297[/tex]

   [tex]A_l=-0.59475[/tex]

b)  [tex]a=0[/tex]

    [tex]a=-0.25175m/s^2[/tex]

Explanation:

From the question we are told that:

Force constant [tex]k=3.05N/m[/tex]

Compression Length [tex]l_c=7.80cm=0.07m[/tex]

Left Mass [tex]M_l=0.400kg[/tex]

Right Mass [tex]M_r=0.800kg[/tex]

Coefficient of kinetic friction [tex]\mu=0, 0.035, and\ 0.397.[/tex]

Therefore

Spring force is given as

 [tex]F_s=Kx[/tex]

 [tex]F_s=3.05*0.070[/tex]

 [tex]F_s=0.238N[/tex]

Generally the equation for Acceleration is mathematically given by

 [tex]A=\frac{F}{m}[/tex]

For Heavier block

 [tex]A_h=\frac{F_s}{m_r}[/tex]

 [tex]A_h=\frac{0.238N}{0.8}[/tex]

 [tex]A_h=0.297[/tex]

For Lighter blocks

 [tex]A_l=\frac{F_s}{m_r}[/tex]

 [tex]A_l=\frac{-0.238N}{0.4}[/tex]

 [tex]A_l=-0.59475[/tex]

b)

Generally the equation for Force is mathematically given by

[tex]F_s-F=ma[/tex]

For Heavier block

[tex]F>Fs[/tex]

Therefore

[tex]a=0[/tex]

For Lighter blocks

[tex]F-F_s=ma[/tex]

[tex](0.035)(0.4)(9.8)-(0.2379)=(0.4)a[/tex]

[tex]a=-0.25175m/s^2[/tex]

Answer: If we leave liquid butane in a bowl on a table in a room where the temperature is [tex]24^{o}C[/tex], butane will evaporate.

Explanation:

A temperature at which the the liquid and gaseous phase of a substance of a substance are present in equilibrium with each other is called boiling point.

For example, the boiling point of butane is -1.5 degree Celsius.

This means that at a temperature above -1.5 degree Celsius, butane will exist is gaseous state. That is, at a temperature of 24 degree Celsius butane will evaporate.

Thus, we can conclude that if we leave liquid butane in a bowl on a table in a room where the temperature is [tex]24^{o}C[/tex], butane will evaporate.

Answer:

Densities increase down the group

MP and BP decrease down the group

Softness increased going down the group

Speed of reacting increases going down the group

Answer:

(a) 37.5 kg

(b) 4

Explanation:

Force, F = 150 N

kinetic friction coefficient = 0.15

(a) acceleration, a = 2.53 m/s^2

According to the newton's second law

Net force = mass x acceleration

F - friction force = m a

150 - 0.15 x m g = m a

150 = m (2.53 + 0.15 x 9.8)

m = 37.5 kg

(b) As the block moves with the constant speed so the applied force becomes the friction force.

[tex]F = \mu m g \\\\150 = \mu\times 37.5\\\\\mu = 4[/tex]

Answer:

Explanation:

They traveled this distance in 2 parts, essentially. Part 1 had an average speed for a certain number of hours, part 2 had an average speed for a certain number of hours, and those 2 parts taken together took them a distance of 364 km. In equation form, that looks like this:

km/hr part 1 + km/hr part 2 = 364 km

Now we need to find each part on the left side of that equation. Part 1 first:

We traveled 65 km/hr for 2 hours, so that took us

[tex]65\frac{km}{hr}*2hr[/tex] and canceling out the hour label, we have that in part 1 we got

65(2) = 130 km. Good. Now onto the second part, where our unknown is.

We traveled 78 km/hr the second part for x hours, so that took us

[tex]78\frac{km}{hr}*xhr[/tex] and canceling out the hour label, we have that in part 2 we got

78x km. Now we can fill in the main equation (the one in bold print)

130 km + 78x km = 364 km and subtracting 130 km from both sides:

78x km = 234 km and dividing by 78 km:

x = 3 hours. Part 2 took 3 hours. Part 1 took 2 hours, so the whole trip took 5 hours.

B. Watts

Then j/s is the rate of transferring energy or doing work. Its unit is the Watt, equivalent to 1 Joule per second.

Answer:  

GIVEN:

v₀=0ms⁻¹

a= 8.1ms⁻²

t= 19.4s

REQUIRE:

d=?

CALCULATUION:

as we know,

d=v₀t+1/2at²

by putting values

d=0ms⁻¹×19.4s+1/2×8.1ms⁻²×(19.4s)²

d=0m+1/2×8.1ms⁻²×376.36s²

d=1/2×3048.516m

d=1524.258m

d≈1524m

Answer:

I don't know.. sorry

Explanation:

help u next time

They are shifted toward the red end of the spectrum.

Answer:

C: time of contact is increased

Explanation:

When a ball is falling from height, it maintains the same mass but velocity may change depending on the conditions in that environment.

Now, to catch the ball on your palm, you need to find a way to reduce the momentum of the ball upon hitting your hand.

Now, to reduce the momentum, we need to apply impulse.

This is because we know that;

Impulse(I) = F × t = change in momentum (m(v - u))

Thus;

I = Ft

F = I/t

We are told that extending the hand reduces the force of contact on your hand.

Thus;

For F which is the force to be reduced, the denominator (t) has to be increased.

Thus, the correct answer is that time of contact is increased

Answer:

The maximum height is 10.0m

The correct option about the free fall motion is "10 m".

A vertically oriented uniformly accelerated motion is referred to as "free-fall" motion. We refer to a vertical movement of an object either upward or downward as being in free fall.

We have given initial velocity (u) as 14 m/s

and we have to find out the maximum height (s)

We know that at maximum height the final velocity (v) will become 0

and acceleration will always be act toward downward

with the value of g = 9.8 m/s²

Applying the first equation

0 = 14 - 9.8t

9.8t = 14

t = 14/9.8 seconds

t = 1.4 seconds

Applying the second equation

s = 14 × 1.4 + ( (1/2) × (-10) × (1.4)² )

s = 19.6 - ( 5 × 1.96 )

s = 19.6 - 9.8

s = 9.8 m

s ≈ 10 m

Thus, we can conclude that if we throw a water balloon straight up with  initial velocity of 14 m/s then the balloon will attain the maximum height of 10 m.

Learn more about free fall here:

https://brainly.com/question/14732889

#SPJ2

Answer:

A meteorologist is a scientist that studies and examines Earth's atmosphere and its interactions with Earth's oceans, land, and biosphere.

Explanation:

Meteorologists use math and science to understand and predict changes in weather and climate.

Answer:

Explanation:

PE = mgh where m is the mass, g is gravity, and h is the height from which the object can potentially fall. We are given enough info here to solve for h. Filling in:

42 = 1.8(9.8)h and

[tex]h=\frac{42}{(1.8)(9.8)}[/tex] and rounding to 2 sig fig's as we need:

h = 2.4 m, choice D

The solubility of the sample will decrease

Answer:

D

Explanation:

a weak base is the answer

Answer:

weak base because its near to 7 (neutral) and above 7 is base

Answer:

f=ma.......m=f/a......m=20kg

Answer:

i. Work done by the gas as it expands is approximately 1,900 J

ii. The total heat supplied is approximately 4, 576 J

iii. The change in internal energy is approximately 2,772 J

Explanation:

The constant pressure of the helium gas, P = 1.0 × 10⁵ Pa

The initial and final pressure of the gas, T₁, and T₂ = 2°C (275.15 K) and 112°C (385.15 K) respectively

The number of moles of helium in the sample of helium gas, n = 2 moles

The volume occupied by the gas at state 1, V₁ = 45 L

i. By ideal gas law, we have;

P·V = n·R·T

Therefore;

[tex]V = \dfrac{n \cdot R \cdot T}{P}[/tex]

Plugging in the values gives;

[tex]V_2 = \dfrac{n \cdot R \cdot T_2}{P}[/tex]

Where;

V₂ = The volume of the gas at state 2

Therefore;

[tex]V_2 = \dfrac{2 \cdot 8.314 \cdot 385.15}{1.0 \times 10^5} \approx 0.064[/tex]

The volume of the gas at state 2, V₂ ≈ 0.064 m³ = 64 Liters

Work done by the gas as it expands, W = P × (V₂ - V₁)

∴ W ≈ 1.0 × 10⁵ Pa × (64 L - 45 L) = 1,900 J

Work done by the gas as it expands, W ≈ 1,900 J

ii. The total heat supplied, Q = Cp·n·ΔT

∴ Q = 20.8 J/(mol·K) × 2 moles × (385.15 K - 275.15 K) = 4,576 J

The total heat supplied, Q = 4, 576 J

iii. The change in internal energy, ΔU = Cv·n·ΔT

∴ ΔU = 12.6 J/(mol·K) × 2 moles × (385.15 K - 275.15 K) = 2,772 J

The change in internal energy, ΔU = 2,772 J