Question

Which equation is equivalent to = 36? = 3 x + 15 = 9 x + 15 = –6 = 24

Answer 1

Answer:

Given that:-

A train running at a speed of 84 km/h

The train crosses a electric pole at 9 seconds

We need to find the length of the train.

Let's Do!

What we can do here, is first convert the given units into SI units.

84 km/h => m/s

1 metre = 1000 km

1 hour = 3600 seconds

\sf{Kmph = \dfrac{1000}{3600} = \dfrac{5}{18} \ After \ simplification}Kmph=

3600

1000

=

18

5

After simplification

So, we can now multiply 84 with 5/18

It was just a shortcut method, you can use it directly as well.

So, we get:-

\sf{\dfrac{84 \times 5}{18}}

18

84×5

\sf{ = 23.33 \ mps \ approximately}=23.33 mps approximately

mps means metre/second.

Now, we know that

\boxed{\sf{Speed = \dfrac{Distance}{Time} }}

Speed=

Time

Distance

\boxed{\sf{\mapsto Distance = Speed \times Time}}

↦Distance=Speed×Time

Now, we need is length ie Distance.

So, 23.33*9 = 209.97 metres is the length of the train.