Question

A meteor moving 468 km per minute traveling in a south-to-north direction passed near Earth in 2013. Because the meteor was only 45 m wide and was 27,700 km above Earth’s surface, it was not visible without the aid of a telescope.Which statement BEST describes the meteor’s motion?
A Its velocity was 7.8 km/s northward
B Its acceleration was 468 kilometers per second squared
C Its speed was 468 km/s northward
D Its acceleration was 7.8 kilometers per second squared

Answer 1

The correct statement is A Its velocity was 7.8 km/s northward. 
In fact, the problem says that the meteor was moving at 468 km per minute. We can convert this value into km/s, keeping in mind that there are 60 seconds in one minute: 1 min=60 s:
$v=468 km/min =(468 km/min)( \frac{1}{60} min/s )=7.8 km/s$