1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
seraphim [82]
3 years ago
14

Two passenger train, A and B, 450 km apart, star to move toward each other at the same time and meet after 2hours.

Mathematics
1 answer:
likoan [24]3 years ago
5 0

Let v be the speed of train A, and let's set the origin in the initial position of train A. The equations of motion are

\begin{cases}s_A(t) = vt\\s_B(t) = -\dfrac{8}{7}vt+450\end{cases}

where s_A,\ s_B are the positions of trains A and B respectively, and t is the time in hours.

The two trains meet if and only if s_A=s_B, and we know that this happens after two hours, i.e. at t=2

\begin{cases}s_A(2) = 2v\\s_B(2) = -\dfrac{16}{7}v+450\end{cases}\implies 2v = -\dfrac{16}{7}v+450

Solving this equation for v we have

2v = -\dfrac{16}{7}v+450 \iff \dfrac{30}{7}v=450 \iff v=\dfrac{450\cdot 7}{30} = 105

So, train A is travelling at 105 km/h. This implies that train B travels at

105\cdot \dfrac{8}{7} = 15\cdot 8=120 \text{ km/h}

You might be interested in
Will give brainlist.. thanks!
Lena [83]
It’s A because of the graph so it’s a
3 0
2 years ago
Read 2 more answers
Which expressions are equivalent to 10/10^3/4
zysi [14]

\dfrac{10}{10^\frac{3}{4}}=10^{1-\frac{3}{4}}=10^\frac{1}{4}=\sqrt[4]{10}\\\\\text{Used:}\\\\\dfrac{a^n}{a^m}=a^{n-m}\\\\\sqrt[n]{a}=a^\frac{1}{n}

3 0
3 years ago
Read 2 more answers
Vicky is renting an apartment.In addition to the first month’s rent, the landlord requires him to pay half of a month's rent as
Slav-nsk [51]

Answer:

  • $2000

Step-by-step explanation:

Let the monthly rent be x.

<u>Then we have:</u>

  • x + 0.5x + 0.4x = 3800
  • 1.9x = 3800
  • x = 3800/1.9
  • x = 2000

Monthly rent is $2000

7 0
3 years ago
Read 2 more answers
Michael invested 5,000 in an account that has a 5.5% annual interest rate. What equation best describes investment after T years
ivolga24 [154]

Answer:

V = 5000 +  275*T   for simple annual interest

or:   A = 5000 * (1.055)^T   for an annual compound interest

Step-by-step explanation:

I assume this is a simple interest rate.  If not I will give the one for compound interest.

V = 5000 + 5000* 0.055 * T      (Value of account after T years)

V = 5000 +  275*T   for simple annual interest

or:   A = 5000 * (1.055)^T   for an annual compound interest

5 0
3 years ago
What are the zeros of f(x) = x2 - 8x+16?
Stels [109]

Answer:

x=4

Step-by-step explanation:

f(x) = x^2 - 8x+16

Set equal to zero

0 = x^2 -8x +16

Factor

what 2 numbers multiply to 16 and add to -8

-4*-4 = 16

-4+-4 = -8

0= (x-4)(x-4)

Using the zero product property

x-4 = 0  x-4 =0

x=4  x=4

3 0
3 years ago
Other questions:
  • a car brought for sh 80,000 was sold through a dealer at a profit of 15% commission on the selling price.how much did the owner
    6·1 answer
  • Please simplify 3/5(25n-10y+5n)<br> please show work
    12·1 answer
  • The combined thickness of the pages of a textbook is 15/16 of an inch each cover is 1/8 of an inch thick what is the thickness o
    8·1 answer
  • I need accurate answer please this is my last attempt
    14·1 answer
  • Please help ill give brainliest
    5·2 answers
  • When a= -5, b = -2 and c=1. a(b+c) is?
    13·1 answer
  • Prove: If the number a+7b is divisible by 17 , then the number 10a+2b is divisible by 17
    5·1 answer
  • Find the area of the shaded region. All angles are right angles.
    12·1 answer
  • Please help. Will give brainlist if correct
    10·2 answers
  • Express each fraction as a decimal:<br><br>- 2 4/100
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!