What goals do investigators have when examining a car accident? How do they know how fast a car that was involved in an accident was going?

--->The goals of the investigators is to prevent tampering with evidence and reduce exposing workers to additional harm.

--> The investigators are able to find out how fast a car that was involved in an accident was going by measuring the length of skid marks.

Explanation:

Automobile or car accidents are incidents which when it occurs are generally fast, violent and confusing to both the people involved and the eyewitnesses. With the development in technology, investigators (usually known as forensic investigators) use a variety of tools and physical evidence to put together a clear picture of what happened during a car accident. With their discoveries, they would be able to to prevent tampering with evidence and reduce exposing workers to additional harm.

They can know how fast a car that was involved in an accident was going by:

--> Analysing a physical evidence such as measurement of the length of skid marks. When the skid distance (which is the drag factor due to road surface friction) and the braking efficiency are determined, the minimum speed of a car as it started skidding can be estimated. Even the appearance of the skid mark also tells investigators whether a car was braking, accelerating, or sliding.

iron would move it is magnetic there is a mag field around the current in the wire