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3 years ago

What percentage of railroad crossing crashes result from a vehicle driving into the side of a train?

1 answer:

8 0

The percentage of railroad crossing crashes that results from a vehicle driving into the side of a train is 25%.
These crashes usually occur as the result of drivers intentionally circumventing warning equipment used at railroad crossings. Drivers typically used their senses to determine the proximity of the train and attempt to cross quickly rather than wait for the train to pass before crossing.

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Please help, and give an explanation on what you did. Thanks a lot :]

34kurt

Answer:

3.0 m

Explanation:

The height of the wave is just 1.5 m + 1.5 m which equals 3.0 m

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3 years ago

A driver in a 2000 kg Porsche wishes to pass to pass a slow-moving school bus on a four-lane road. What is the average power in

creativ13 [48]

Answer:

The power require to accelerate the car is, P = 299700 watts

Explanation:

Give data,

The mass of the car, m = 2000 kg

The initial velocity of the sports car, u = 30 m/s

The final velocity of the sports car, v = 60 m/s

The time period of acceleration, t = 9 s

The acceleration of the car, a = (v-u) / t

= (60 - 30) / 9

= 3.33 m/s²

The displacement of the car,

S = ut + ½ at²

= 30 x 9 + ½ x 3.33 x 9²

= 405 m

The force acting on the car, F = m x a

= 2000 x 3.33

= 6660 N

The work done by the car, W = F S

= 6660 x 405

= 2697300 J

The power of the car, P = W / t

= 2697300 / 9

= 299700 watts

Hence, the power require to accelerate the car is, P = 299700 watts

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4 years ago

How is aquatic biome classification different from terrestrial biome classification?

Mariana [72]

It’s by making baby’s with baby boomers

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3 years ago

Read 2 more answers

The British gold sovereign coin is an alloy of gold and copper having a total mass of 7.988 g, and is 22-karat gold 24 x (mass o

matrenka [14]

Answers:

(a) $0.0073kg$

(b) Volume gold: $3.79(10)^{-7}m^{3}$ , Volume cupper: $7.6(10)^{-8}m^{3}$

(c) $17633.554kg/m^{3}$

Explanation:

We are told the total mass $M$ of the coin, which is an alloy of gold and copper is:

$M=m_{gold}+m_{copper}=7.988g=0.007988kg$ (1)

Where $m_{gold}$ is the mass of gold and $m_{copper}$ is the mass of copper.

In addition we know it is a 22-karat gold and the relation between the number of karats $K$ and mass is:

$K=24\frac{m_{gold}}{M}$ (2)

Finding ${m_{gold}$ :

$m_{gold}=\frac{22}{24}M$ (3)

$m_{gold}=\frac{22}{24}(0.007988kg)$ (4)

$m_{gold}=0.0073kg$ (5) This is the mass of gold in the coin

<h2>(b) Volume of gold and cupper</h2><h2 />

The density $\rho$ of an object is given by:

$\rho=\frac{mass}{volume}$

If we want to find the volume, this expression changes to: $volume=\frac{mass}{\rho}$

For gold, its volume $V_{gold}$ will be a relation between its mass $m_{gold}$ (found in (5)) and its density $\rho_{gold}=19.30g/cm^{3}=19300kg/m^{3}$ :

$V_{gold}=\frac{m_{gold}}{\rho_{gold}}$ (6)

$V_{gold}=\frac{0.0073kg}{19300kg/m^{3}}$ (7)

$V_{gold}=3.79(10)^{-7}m^{3}$ (8) Volume of gold in the coin

For copper, its volume $V_{copper}$ will be a relation between its mass $m_{copper}$ and its density $\rho_{copper}=8.96g/cm^{3}=8960kg/m^{3}$ :

$V_{copper}=\frac{m_{copper}}{\rho_{copper}}$ (9)

The mass of copper can be found by isolating $m_{copper}$ from (1):

$M=m_{gold}+m_{copper}$

$m_{copper}=M-m_{gold}$ (10)

Knowing the mass of gold found in (5):

$m_{copper}=0.007988kg-0.0073kg=0.000688kg$ (11)

Now we can find the volume of copper:

$V_{copper}=\frac{0.000688kg}{8960kg/m^{3}}$ (12)

$V_{copper}=7.6(10)^{-8}m^{3}$ (13) Volume of copper in the coin

<h2>(c) Density of the sovereign coin</h2><h2 />

Remembering density is a relation between mass and volume, in the case of the coin the density $\rho_{coin$ will be a relation between its total mass $M$ and its total volume $V$ :