I found an answer from www.quora.com

How much work is required to accelerate a 1000 **kg car** from 20 m/s ...

The work done is the **same** as the amount of energy increase. ... The change **in**
**kinetic energy** denoted by ∆**KE** is **equal** to the final **KE** - the ... What is the force
required to stop a **car** of **mass** 100kg with **two** passengers of ... on a body of **mass**
10 **kg** and changes its velocity from 2 metre per **second** to 5 ... For the **first** case:

For more information, see How much work is required to accelerate a 1000 **kg car** from 20 m/s ...

I found an answer from www.scientificamerican.com

The Bicycle Problem That Nearly Broke Mathematics - Scientific ...

Jul 20, 2016 **...** The handmade frame that he got as a wedding present is coated **in** fine dust. ... “
We are all stuck **in** the nineteenth century, when **there** wasn't such a ... The **first**
patents for the velocipede, a **two**-wheeled precursor to the bike, date to 1818 ...
bicycle-science nerds and helped to build a **car** that fitted into a few ...

For more information, see The Bicycle Problem That Nearly Broke Mathematics - Scientific ...

The kinetic energy formula is \frac{1}{2}mv^{2}, where m is the mass and v is the velocity in km/hr.

The mass of both the objects are the same, but the velocity for the first car say v_{1}= 90 \frac{km}{hr} = 25 \frac{m}{s}

The velocity of the second car say v_{2} = 54\frac{km}{hr} = 15 \frac{m}{s}

So, we have the ratio of K.E of the two cars as

\frac{1}{2}mv_{1}^{2} : \frac{1}{2}mv_{2}^{2}

The like terms gets cancelled and we are left with v_{1}^{2} : v_{2}^{2}

Plugging in v_{1} = 25 and v_{2}= 15 we get 25^{2} : 15^{2}

= 625 : 225

= 25 : 9

Here is how you can convert km/hr to m/s

https://byjus.com/questions/how-do-you-convert-km-h-to-m-s/

Here is how you can express a ratio in the simplest form