Answers
Answer:
The average speed is 22.2 km/h
Explanation:
Average Speed
Given an object travels a total distance d and took a total time t, then the average speed is:
[tex]\displaystyle \bar v=\frac{d}{t}[/tex]
The mailman first drives d1=7 km at v1=15 km/h. The time taken to drive is:
[tex]\displaystyle t1=\frac{d1}{v1}=\frac{7}{15}=0.467\ h[/tex]
Then he drives d2=7 km at v2=43 km/h taking a time of:
[tex]\displaystyle t2=\frac{d2}{v2}=\frac{7}{43}=0.163\ h[/tex]
The total time is
t=0.467 h + 0.163 h = 0.63 h
The total distance is
d = 7 km + 7 km = 14 km
The average speed is:
[tex]\displaystyle \bar v=\frac{14}{0.63}=22.2\ km/h[/tex]
The average speed is 22.2 km/h
Related Questions
what is the state of y when y = k/x, x is halved.
Answers
Answer:
y becomes doubled.
Explanation:
If;
y = [tex]\frac{k}{x}[/tex]
what is the state of y when x is halved;
the given expression is an inverse relationship. When y increases, x is supposed to decrease and vice versa.
if x is halved; x = [tex]\frac{x}{2}[/tex]
[tex]\frac{k}{\frac{x}{2} }[/tex] = [tex]\frac{2k}{x}[/tex]
Now compare :
[tex]\frac{k}{x}[/tex] : [tex]\frac{2k}{x}[/tex]
we see that y becomes doubled
An arrow in a bow has 357 J of elastic potential energy How much Winette enere
Will the arrow have after it has been shot assuming there is no sir restoran
Answers
Answer:
357 J
Explanation:
The elastic potential energy of arrow in the stretched bow is 357 J.
The kinetic energy of the arrow after it has been shot is given by half of the product of the arrow's mass and velocity of the arrow.
Here there are no other forms of energy at play here. Only potential and kinetic energy.
As we know that in any system the energy is conserved accordingly the elastic potential energy of the arrow will be equal to the kinetic energy of the bow after it is released i.e., 357 J.
A shell traveling with speed, v0 , exactly horizontally and due north explodes into two equal mass fragments. It is observed that just after the explosion one fragment is traveling vertically up with speed v0 . What is the velocity of the other fragment? Hint: Velocity has both magnitude and direction.
Answers
Answer:
yeah
Explanation:
yeah yeah yeah yeah
"She finished the sprint with the speed of a cheetah." This statement represents which of the
following functions of language? (2 points)
correct answer is poetic.
Answers
Answer:
Poetic
Explanation:
I took the test
Answer:
Poetic
Explanation:
I got it right on the test
How does the abundance of hydrogen and helium support the Big Bang Theory?
Answers
It is the proportion predicted to be present in the early universe.
The hydrogen and helium abundance helps us to model the expansion rate of the early universe.
In the abundance of hydrogen and helium, we can say that they account for nearly all the nuclear matter in today's universe.
In big Bang model, the universe is mostly light or protons.
This abundance of hydrogen and helium is consistent with this big bang model. The process of forming this hydrogen and helium is often called big bang nucleosynthesis.The Schramm's model for relative abundances indicate that helium is about 25% by mass and hydrogen about 73% with all other elements constituting less than 2%.
Several proponents of big Bang theory has proposed similar relative abundance for hydrogen and helium. In all it is clear that hydrogen and helium constitute of more than 98% of the ordinary matter in the universe.
Finally, the hydrogen and helium abundance helps us to model the expansion rate of the early universe.
Learn more here: https://brainly.com/question/24439982
A 2.0 cm thick brass plate (k_r = 105 W/K-m) is sealed to a glass sheet (kg = 0.80 W/K m), and both have the same area. The exposed face of the brass plate is at 80°C, while the exposed face of the glass is at 20 °C. How thick is the glass if the glass brass interface is at 65 C? Ans. 0.46 mm