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
MariettaO [177]
4 years ago
8

Two trains travel at right angles to each other after leaving the same train station at the same time. Two hours later they are

70.46 miles apart. If one travels 9 miles per hour slower than the other, what is the rate of the faster train? (Round your answer to the nearest integer)
Physics
2 answers:
trasher [3.6K]4 years ago
6 0

Answer:

The faster train travels at a speed of 29 miles/hr    

Explanation:

Let the speed of train A be x miles/hr

So the speed of the train B is ( x - 9 ) miles/hr

After two hours, their speed will be 2x and 2( x - 9 ) respectively. and the distance between them is 70.46 miles.

So using Pythogorus theorem, we can write

(2x)^{2}+(2x-18)^{2} = 70.46^{2}

8x^{2}-72x+324 = 4964.6116

8x^{2}-72x-4640.6116 = 0

On solving the above equation we get

x = 29.0015 miles/hr

 = 29 miles/hr

Therefore the faster train travels at a speed of 29 miles/hr

Vikentia [17]4 years ago
3 0

Answer:

Speed of faster train equals 29 mph

Explanation:

Let the speed of slower train be 'x' miles per hour and the speed of faster train be 'y' miles per hour.

Distance that slower train covers in 2 hours=2\times x miles

Distance that faster train covers in 2 hours=2\times y miles

Since they move at right angles the distance between them can be found by Pythagoras formula as

d^{2}=(2x)^{2}+(2y)^{2}\\\\d^{2}=4(x^{2}+y^{2})\\(70.46)^{2}=4(x^{2}+y^{2})\\\\\therefore (x^{2}+y^{2})=\frac{(70.46)^{2}}{4}\\\\(x^{2}+y^{2})=\frac{4964.6}{4}\\\\(x^{2}+y^{2})=1241.15

It is given that y=x+9

Using this in the above equation we get

(x^{2}+y^{2})=1241.15\\\\x^{2}+(x+8)^{2}=1241.15\\2x^{2}+16x+64=1241.15\\2x^{2}+16x-1177.15=0

This is a quadratic equation in 'x'

Comparing with standard quadratic equation ax^{2}+bx+c we get value of x as

(x^{2}+y^{2})=1241.15\\\\x^{2}+(x+8)^{2}=1241.15\\2x^{2}+16x+64=1241.15\\2x^{2}+16x-1177.15=0\\\\x=\frac{-16\pm \sqrt{(16)^{2}-4\times 2\times -1177.15}}{2\times 2}\\\\x=\frac{-16\pm 98.35}{4}\\\\x=20.58mph(\because speed\neq

Thus speed of faster train = 28.58 mph

Speed of faster train = 19 mph

You might be interested in
If a 580 N net force acts on a 40 kg what will the acceleration of the car be
myrzilka [38]

Answer:

I think u have to do 580N times 40KG

7 0
3 years ago
Read 2 more answers
An experimental tungsten light bulb filament has a length of 5 cm and a diameter of 0.074 cm. The filament is basically just a w
adell [148]

Answer:

power emitted is 1.75 W

Explanation:

given data

length l = 5 cm = 5 ×10^{-2} m

diameter d = 0.074 cm = 74 ×10^{-5} m

total filament emissivity = 0.300

temperature = 3068 K

to find out

power emitted

solution

we find first area that is π×d×L

area = π×d×L

area = π×74 ×10^{-5}×5 ×10^{-2}

area = 1162.3892  ×10^{-5} m²

so here power emitted  is express as

power emitted  = E × σ × area × (temperature)^4

put here all value

power emitted  = 0.300× 5.67 × 1162.3892  ×10^{-5}  × (3068)^4

power emitted = 1.75 W

5 0
3 years ago
How much time does it take for a rattlesnake to strike its victim if it is strikes at a speed of 1.25 m/s and the victim is exac
Marianna [84]

Answer:

4 seconds

Explanation:

5/1.25=4

6 0
3 years ago
Oceans and other bodies of water are found on which layer of earth
satela [25.4K]

Answer:

They are found in the Hydrosphere

Explanation:

holped it helped!!

7 0
2 years ago
What must a system owner do, once the threshold leak rate has been exceeded on any low-pressure system using an ozone-depleting
soldier1979 [14.2K]

Answer:

A procedure according to the norms.

Explanation:

If possible, proceed to fix the leak in no more than 30 days from the moment it was discovered.

Otherwise, during the first 30 days develop a planification to backfit the leak or, if needed, retire the appliance. This should be executed within one year.

7 0
3 years ago
Other questions:
  • Explain the flow of electrons from the battery through the circuit
    14·1 answer
  • Which of the following describes a chemical change
    15·2 answers
  • Which two objects have stored energy?
    14·2 answers
  • Identify the smallest unit of an element
    13·2 answers
  • Which of the following can carry light waves but not sound waves
    14·2 answers
  • A mixture of iron and sulfur can be separated by
    7·2 answers
  • A skier descends a mountain at an angle of 35.0º to the horizontal. If the mountain is 235 m long, what are the horizontal and v
    10·1 answer
  • Do you think antiseptic creams and lotions play an important part in our day<br>to day life? ​
    7·2 answers
  • It took Lightning McGreen 2.5 hours to travel
    6·2 answers
  • How many stars are in a galaxy? hundreds thousands millions billions.
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!