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
harkovskaia [24]
3 years ago
5

Two cities are 45 miles apart. Two trains, with speeds of 70 mph and 60 mph, leave the two cities at the same time so that one i

s catching up to the other. How long after the trains leave will the distance between them be 10 miles? How long after the trains leave will they be 10 miles apart for the first time? What about the second? PLEASE HELP ASAP I WILL MARK BRAINLIEST
Mathematics
2 answers:
KATRIN_1 [288]3 years ago
4 0

The distance between the trains is changing at the rate of (70 -60) = 10 mph. They will be in the same place (45 mi)/(10 mi/h) = 4.5 hours after they leave their respective cities. They will be 10 miles apart both 1 hour before that time and one hour after that time.

The trains will be 10 miles apart 3.5 hours after leaving.

They will be 10 miles apart the second time 5.5 hours after leaving.

Liula [17]3 years ago
3 0

so basically, one train has a head start of 45 miles

we assume that the slower train has the head start because if the faster train had the head start, then faster train would just get farther and farther away from the slower train (distance≥45mi for all time)


so

set a 0 point

lets say that at t=0, fast train has traveled 0 and slow train has traveled 45

distance=speed times time+headstart

so dist_fast=70*t+0=70t

dist_slow=60*t+45=60t+45


when will the distance between them be 10?

there will be a time when slower train will be in front and when fast train will be in front

when slow train is in front, dist_slow-dist_fast=10 or

60t+45-70t=10

solve for t

60t+45-70t=10

-10t+45=10

minus 45 both sides

-10t=-35

divide both sides by -10

t=-3.5 hrs



when fast train is ahead, dist_fast-dist_slow=10

70t-(60t+45)=10

70t-60t-45=10

10t-45=10

add 45 to both sides

10t=55

divide both sides by 10

t=5.5 hrs





so after 3.5hrs is the first time they are 10 miles apart

after 5.5 hours is the 2nd time they are 10 miles apart

You might be interested in
A hot air balloon holds 1,592 cubic meters of helium. The density of helium is 0.1785 kilograms per cubic
yuradex [85]

Answer: 285.2 kg

Step-by-step explanation:

Given

The volume of helium in the balloon is V=1592\ m^3

The density of the helium is \rho =0.1785\ kg/m^3

Mass of the helium gas is given by the product of density and volume

\Rightarrow M=\rho \cdot V\\\Rightarrow M=0.1785\times 1592\\\Rightarrow M=285.2\ kg

Thus, the mass of gas is 285.2 kg

3 0
2 years ago
Hey I need help on a question real fast the question is if three equals B times seven then seven times be equals what
bonufazy [111]

Answer would be 14b.

3 0
3 years ago
Se pot aduce fracțiile la același numitor prin simplificare?
Vlad [161]
Can you please put this question in english

8 0
3 years ago
Solve for d.<br> a - C= d - r
MArishka [77]

Answer:

a - C + r = d

Step-by-step explanation:

a - C = d - r

add r to both sides

a - C + r = d

6 0
2 years ago
I WILL GIVE BRAINLIEST IF YOUR ANSWER IS CORRECT
telo118 [61]

Answer:

1. 4.5 g

2. 56.25 g

Step-by-step explanation:

3 % substance solution means :

3 g of dry substance is present in 100 g of solution.

By unitary method:

The weight of dry substance in 1 g of solution = \frac{3}{100}

The weight of dry substance in 150 g of solution = \frac{3}{100}\times150=4.5\ g

Let the weight of solution be w.

8 % solution contains 8 g dry substance in 100 g.

We have to find the weight of the solution(w) which contains 4.5 g of dry substance.

⇒ \frac{8}{100}\times w=4.5\\w=\frac{450}{8}=56.25\ g.

6 0
3 years ago
Other questions:
  • An electrician charges a set fee of $100 for every house call and then charges an additional hourly rate. One day, the electrici
    13·2 answers
  • What is the Value of x? <br> 30 = x -17
    13·2 answers
  • Find the coordinates of the midpoint MM of ST. Then find the distance between points SS and TT. Round the distance to the neares
    7·1 answer
  • 13 1/10-7 9/10<br><br> i need help
    9·2 answers
  • BRAINLIEST AND 50 PTS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!HURRY!!!!!!!!!!!!!
    14·1 answer
  • 5/6 is equivalent to a percent that is larger than 100%. <br><br> True or False<br><br> 13 pts.
    7·2 answers
  • Complete the problem <br> 5/10 + 8/100 =
    8·1 answer
  • Brent bought shirts for $50. Each shirt cost $10. How many shirts did he buy?
    6·2 answers
  • Find the value of x 7x+2=16<br>pls explain​
    12·2 answers
  • Suppose c and d vary inversely, and d=2 when c=17.
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!