An object has an acceleration of 18.0 m/s/s. If the net force

If a train is going 60 m/s hits the brakes, and it takes the train 1 minute 25 seconds to stop, what is the train’s acceleration

Cloud [144]

Hey there, the answer is .............................. About 0.7 m/sec^2

Acceleration is the change in speed / time 

Change in speed is 60 m/sec 

Time is 1 minute 25 second. Convert that to seconds. 

Divide the change in speed by the time in seconds.

About 0.7 m/sec^2

So the acceleration is - 60 / 85 = - 0.71 m/s^2

HOPE I HELPED!!!!!!!!!!

8 0

3 years ago

An iron railroad rail is 800 ft long when the temperature is 31°C. What is its length (in ft) when the temperature is −17°C?

natta225 [31]

Answer:

799.54 ft

Explanation:

Linear thermal expansion is:

ΔL = α L₀ ΔT

where ΔL is the change in length,

α is the linear thermal expansion coefficient,

L₀ is the original length,

and ΔT is the change in temperature.

Given:

α = 1.2×10⁻⁵ / °C

L₀ = 800 ft

ΔT = -17°C − 31°C = -48°C

Find: ΔL

ΔL = (1.2×10⁻⁵ / °C) (800 ft) (-48°C)

ΔL = -0.4608

Rounded to two significant figures, the change in length is -0.46 ft.

Therefore, the final length is approximately 800 ft − 0.46 ft = 799.54 ft.

7 0

3 years ago

4. The atmosphere is composed of about 78% nitrogen, 21% oxygen, and 1% argon. Typical atmospheric pressure in Boulder, Colorado

photoshop1234 [79]

ANS

Step 1 :Explanation of required formula.

According to Dalton's Law of Partial Pressures, the partial pressure of a component of a gaseous mixture depends on the mole ratio of said component and the total pressure of the gaseous mixture

i.e Pi=Xi × Ptotal,

Here we don't know exactly how many moles of the mixture we have,

but we know that 78.0% of all the molecules present in the mixture are nitrogen molecules, 21.0% are oxygen molecules, and 1% are molecules of Ar gas.

As we know, a mole is simply a very large collection of molecules. In order to have one mole of a substance, we need to have 6.022 × 1023 molecules of that substance.

This means that the actual number of moles is not important here, because the ratio that exists between the number of molecules is equivalent to the ratio that exists between the number of moles.

Hence,

Step 2 : Calculate of mole fraction of the mixture.

mole fraction of nitrogen = 78 /100 = 0.78

mole fraction of O2 =

21 /100 = 0.21

mole fraction of Argon =

1 /100 = 0.01.

Step 3 : Calculate the pressure contributed by each of the mixture.

The pressure contributed by N2 = mole fraction of N2 × Total pressure = 0.78 × 0.83 atm = 0.6474 atm

The pressure contributed by O2 = 0.21 × 0.83 atm = 0.1743 atm

The pressure contributed by N2 = 0.01 × 0.83 atm = 0.0083 atm.

Thank You !!!!!!

6 0

3 years ago

Which of the following is not an application of Doppler technology?

allsm [11]

The correct answer to the question above is The third Option: C; ultrasound imaging of the liver. The ultrasound imaging of the liver is definitely not an application of Doppler technology.

Hope this helps! :)

8 0

3 years ago

Read 2 more answers

6x10^8 kg ————— 2x10^4 m^3

barxatty [35]

The answer to the question

4 0

3 years ago