# Find km/h with Kinetic Energy and mass?

Sorry for the picture the math formatting is very hard. I'm trying to answer the exercise 4 which asks for (title). The info given is: Kinetic energy: $$6,73*10^-19$$ Mass: $$9,109*10^-31$$ My problem isn't the question itself it's actually only what happens when it goes from one step to $$sqrt(1,50*10^12)$$ Again sorry for the formatting but I've been trying to do it for like an hour already. Unfortunately I can't post a picture. http://imgur.com/gallery/BGRZYC6

## 1 Answer

It was just simplifying the expression: $$\sqrt{\frac{2\times6.73\times10^{-19}}{9.109\times10^{-31}}}=\sqrt{1.50\times 10^{12}}=1.22\times10^6 \text{ m/s}.$$

• Hi, thanks for the answer, but that's just what's written in the solutions. My problem is, what happened there to simplify it. What happened between step one and two you just wrote there. Thanks. – Yves Bonneau Sep 22 '19 at 20:14
• Have you learned division of scientific notation? If not, read here: en.wikipedia.org/wiki/Scientific_notation#Basic_operations – Gabe Nov 30 '19 at 14:02