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egoroff_w [7]
3 years ago
15

A van moves 50 miles with a constant speed of 20 mph and another 84 miles with a constant speed of 56 mph. How much time in tota

l does it take to travel these distances?
A) 1 hour
B) 4 hours
C) 1.5 hours
D) 2.5 hours
Chemistry
1 answer:
arlik [135]3 years ago
3 0

Answer:

B) 4 hours

Explanation:

the equation relating speed , distance and time is as follows

speed = distance / time taken

the van moves 50 miles at 20 mph and the next 84 miles at 56 mph

so lets calculate the time taken at both speeds

substituting the values in the above equation

20 mph = 50 miles  / time

time taken = 50 / 20 = 2.5 hours

56 mph = 84 miles / time

time taken = 1.5 hours

the totat time taken is - 2.5 + 1.5 = 4 hours

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Luba_88 [7]
<h2>Answer:  125.41 mL</h2>

Explanation:

Volume = mass ÷ density

             =  116 g  ÷  0.925 g/mL

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<h3>A 116 g of sunflower oil of 0.925 g/mL has a volume of 125.41 mL.</h3>
7 0
3 years ago
What is the direction of the polarity of the indicated bond in h3c−oh marked by δ+ and δ−?
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Answer:- The direction of the polarity of the indicated bond is from carbon to oxygen.

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Oxygen is more electron negative than carbon. So, being more electron negative, the bonding electrons are more towards oxygen and it cases partial negative charge on oxygen and partial positive charge on carbon. The direction of the polarity is from less electron negative carbon to more electron negative oxygen.

It is shown in the diagram below:


6 0
3 years ago
The ideal gas heat capacity of nitrogen varies with temperature. It is given by:
hammer [34]

Answer:

A)  1059 J/mol

B)  17,920 J/mol

Explanation:

Given that:

Cp = 29.42 - (2.170*10^-3 ) T + (0.0582*10^-5 ) T2 + (1.305*10^-8 ) T3 – (0.823*10^-11) T4

R (constant) = 8.314

We know that:

C_p=C_v+R

We can determine C_v from above if we make C_v the subject of the formula as:

C_v=C_p-R

C_V = 29.42-(2.7*10^{-3})T+(5.82*10^{-7})T2-(1.305*10^{-8})T3-(8.23*10^{-12})T4-8.314

C_V = 21.106-(2.7*10^{-3})T+(5.82*10^{-7})T2-(1.305*10^{-8})T3-(8.23*10^{-12})T4

A).

The formula for calculating change in internal energy is given as:

dU=C_vdT

If we integrate above data into the equation; it implies that:

U2-U1=\int\limits^{500}_{450}(21.106-(2.7*10^{-3})T+(5.82*10^{-7})T2-(1.305*10^{-8})T3-(8.23*10^{-12})T4\,) du

U2-U1=\int\limits^{500}_{450}(21.106-(2.7*10^{-3})T/1+(5.82*10^{-7})T2/2-(1.305*10^{-8})T3/3-(8.23*10^{-12})T4/4\,)

U2-U1= 1059J/mol

Hence, the internal energy that must be added to nitrogen in order to increase its temperature from 450 to 500 K = 1059 J/mol.

B).

If we repeat part A for an initial temperature of 273 K and final temperature of 1073 K.

then T = 273 K & T2 = 1073 K

∴

U2-U1=\int\limits^{500}_{450}(21.106-(2.7*10^{-3})T/1+(5.82*10^{-7})T2/2-(1.305*10^{-8})T3/3-(8.23*10^{-12})T4/4\,)

U2-U1=\int\limits^{500}_{450}(21.106-(2.7*10^{-3})273/1+(5.82*10^{-7})1073/2-(1.305*10^{-8})T3/3-(8.23*10^{-12})T4/4\,)

U2-U1= 17,920 J/mol

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7 0
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Answer:
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Explanation:
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