Question

how much distance is covered by an object lying at 45 km/h will cover in 10 sec?​

Answer 1

Given:

Speed = 45 km/h

Time = 10 seconds

To Find:

The distance covered by the object.

Solution:

Here, it is given that the speed of the object is 45 km/h and and the time is 10 seconds. As the units are different, we can first convert km/h to m/s.

This can be done by multiplying the value with 5/18.

$\sf{\longrightarrow\:45\times\dfrac{5}{18}}$

Cancelling further:

$\sf{\longrightarrow\:5\times\dfrac{5}{2}$

$\sf{\longrightarrow\:\dfrac{25}{2}}$

Also, we know that:

$\sf{\longrightarrow\:Speed=\dfrac{Distance}{Time}}$

Substituting the values we know into the equation:

$\sf{\longrightarrow\:\dfrac{25}{2}=\dfrac{Distance}{10}}$

$\sf{\longrightarrow\:\dfrac{25}{2}\times10=Distance}$

$\sf{\longrightarrow\:Distance=125\:m}$

Therefore, the distance covered by the object is 125 m in 10 seconds.

Knowledge Bytes:

Distance: Distance is the total pathlength covered by an object.

Speed: Speed is a scalar quantity obtained by dividing the distance covered by the object by the time taken to cover the object.

Converting km/h to m/s: To convert km/h to m/s, multiply the value by 5/18.

Answer 2

In this question, we are given that the speed of the object = 45km/h.

And we need to find

• The distance covered by the object in 10 seconds

Let's begin. First, we will have to convert the km/h given to m/s in order to find the distance covered in one second.

The question arises as to how to convert km/h into m/s.

$\sf{1 km/hr = \dfrac{1000 meter}{3600 seconds}}$

- which can be simplified to 5/18.

Therefore: we multiply the given value by 5 and then divide it by 18.

45 x (5/18) = 225/18 = 25/2

Using long division method to simplify 25/2:

$\sf\Large\qquad\quad12.5\\ \begin{array}{cc} \cline{2 - 2}\sf 2 )&\sf \ 25.0\\&\sf - 24 \downarrow\\ \cline{2-2}& \sf \ \ \ \ 10\\ &\sf \ - 10 \\ \cline{2-2} & \sf \ \0x \\ \cline{2-2} \end{array}$

And so, we get 12.5 meter/second.

But not to worry about the decimal point, we still have to multiply it by 10 to get the distance for 10 seconds.

12.5 x 10 = 125 meter / 10 seconds.

• Therefore, the object will cover 125 meter in 10 seconds.

Kindly check the attachment if the long division working is not visible :)