# A bullet is shot from the East Coast of the USA and reaches the West Coast of the USA in 4.5 seconds. How fast is that in kilometers per hour?

##### 1 Answer

4.5 seconds;

#### Explanation:

I'm going to tackle this, with a couple of assumptions:

- There is no wind resistance, and
- There is no bullet deflection (aside from what is needed to deal with the curvature of the Earth - 3240 miles being roughly the distance between the East and West coasts of the USA.

To solve for time in the air, we use:

We know

The velocity of the bullet in

Just for fun, let's figure out how far that is.

The ISS (International Space Station) is at an altitude of 6371 + 400 = 6771 km from the centre of the Earth (the 6371 is the radius of the Earth and the 400 is the ISS altitude from the surface). Using the circumference of a circle:

Our bullet would travel roughly 6,260,000 km in an hour and a half, meaning in the time the ISS orbited the Earth once, the bullet would do so close to 150 times.