What units are assumed for speed limit signs in the United States

What is the original source of energy for gasoline?

Yuki888 [10]

Gasoline comes from petroleum, which is a fossil fuel. Petroleum, coal and natural gas (methane) are all made in the earth's crust from the bodies of plants and animals that died long ago. That's why they are called fossil fuels.

The sun provides the energy that all life needs to grow and reproduce. Therefore, fossil fuels can be considered a form of solar energy that has been stored in the bodies of living things, and then concentrated in hydrocarbon deposits in the earth's crust.

The fact is that all the energy on earth comes from the sun, directly or indirectly, except for nuclear energy, which comes from radioactive elements that were made in other stars that existed before the sun.

Hope this helps!!!

5 0

3 years ago

Read 2 more answers

A soccer ball is rolling across a soccer field. The system consists of the

neonofarm [45]

Answer:

NEGATIVE

Explanation:

5 0

3 years ago

A ski lift has a one-way length of 1 km and a vertical rise of200m. The chairs are spaced 20 m apart, and each chair can seatthr

Strike441 [17]

Answer:

a) 68.125 KW

b) 43.04 KW

Explanation:

Distance =d= 1 km

Height = h = 200 m

Spacing between chairs =D= 20 m

No. of people per chair = 3

Speed = V= 10 km/h= 10000m\3600 s=2.8 m/s

mass of chair = 250 kg

Work to operate sky lift

W= mgh

Number of chairs any moment operational = N= 1 km/20=1000m/20=50

So, total mass of chairs = 50 × 250 =12500kg

so, w= mgh=12500×9.8×200=2452500 j

Power is rate of work - we need time for operation time of lift

Time= t = distance/speedf= 1km/(10km/h)=1km/(10 km/3600s)=360s

So, Power P= Work/time=w/t=12500/360=68125 j/s=68.125 KW

Now calculating power for operating speed in 5 sec

We calculate accelleration=a for 5 sec

a= speed / time= V/52.8/5=0.28 m/sec2

for vertical acceleration we calculate θ angle first;

tanθ= height /distance= 200/1000= 0.2

==> θ=11.34°

Vertical acceleration = a₁=a sinθ= 0.28× sin 11.34=0.10835 m/sec2

to calculate height gained during startup use;

S=vit+1/2at2

here s=H

vi=0m/s

t=5 sec

==> H = 0+1/2a₁×t=0.5×0.10835 ×5²=0.5×0.10835×5×5=1.362 m

Total Work =mgH+0.5×m×V²=12500(9.8×1.362+0.5×2.8×2.8)=215240.56 j

Again power = work / time=215240.56/5=43048.112 W=43.04 KW

6 0

2 years ago

A parallel-plate capacitor is held at a potential difference of 250 V. A proton is fired toward a small hole in the negative pla

MissTica

Answer:

The speed of proton when it emerges through the hole in the positive plate is $2.05\times 10^5\ m/s$ .

Explanation:

Given that,

A parallel-plate capacitor is held at a potential difference of 250 V.

A A proton is fired toward a small hole in the negative plate with a speed of, $u=3\times 10^5\ m/s$

We need to find the speed when it emerges through the hole in the positive plate. It can be calculated using the conservation of energy as :

$qV=\dfrac{1}{2}mv^2-\dfrac{1}{2}mu^2\\\\1.6\times10^{-19}\times250=\dfrac{1}{2}mv^2-\frac{1}{2}\cdot1.67\times10^{-27}\cdot(3\times10^{5})^{2}\\\\\dfrac{1}{2}mv^2=3.515\cdot10^{-17}\\\\v=\sqrt{\dfrac{3.515\cdot10^{-17}\cdot2}{1.67\times10^{-27}}}\\\\v=2.05\times 10^5\ m/s$

So, the speed of proton when it emerges through the hole in the positive plate is $2.05\times 10^5\ m/s$ .

5 0

3 years ago

39 liters of water at

Harman [31]

Answer:

Temperature of the mixture=8 °C

Explanation:

Let, Temperature of the mixture=t °C

Q₁ = Q₂

=> m₁SΔΘ₁ = m₂SΔΘ₂

=> 39 × (20+t) = 21 × (60-t)

∴ t = 8 °C

hope you have understood this

pls mark it as the brainliest

3 0

3 years ago