Math, asked by rubiguptamrzgrd, 4 days ago

A train traveling at a uniform speed passes a 455 meter long platform in 17 seconds and another platform. 175 meter long in 10 seconds. find the length and speed of the train.

Answers

Answered by vaibhavkumargames
0

Answer:

Given, 3x

2

+5x+2=0

On comparing this equation with ax

2

+bx+c=0, we get a=3,b=5 and c=2

Now, b

2

−4ac=(5)

2

−4×3×2

=25=24

=1

x=

2a

−b±

b

2

−4ac

==

2×3

−5±

1

=

6

−5±1

x=

6

−5+1

x=

6

−5−1

3

−2

and −1 are the roots of the given quadratic equation.

Answered by alonejatti
0

Let the speed of the train be 's' m\sec

and length of train be 'L' m.

Given Equation: Bridge of distance 275 m and time is 15 seconds.

Bridge of distance 425 m and time is 21 seconds.

Factor to consider is length of Train.

Hence total length =Bridge length+Length of train

According to the formula:

Speed =

Time

Distance

Equation 1 . s =

15

L+275

Similarly for equation 2. s=

21

L+425

From Equation 1 and Equation 2.

15

L+275

=

21

L+425

21×(L+275)=15×(L+425)

21×L+21×275=15×L+15×425

6×L=600

L=100 m.

To calculate speed of train Substitute value of L in equation 1 or equation 2.

Equation 1.

s=

15

L+275

s=

15

100+275

= 25 m\s

To calculate speed in km\hr.

1km = 1000 m

1 hr = 3600 sec

1 m\sec =

1000

3600

=

5

18

25 m\sec =25×(

5

18

) km\hr

= 90 km\hr

Similar questions