Answer:
remove contamination; pollution ; test ground water and dirt .
Acceleration = (change in speed) / (time for the change)
- 4.1 m/s² = (-9 m/s) / (time for the change)
Time for the change = (-9 m/s) / (-4.1 m/s²) = 2.2 seconds
<h2>
Answer: Toward the center of the circle.</h2>
This situation is characteristic of the uniform circular motion , in which the movement of a body describes a circumference of a given radius with constant speed.
However, in this movement the velocity has a constant magnitude, but its direction varies continuously.
Let's say 
is the velocity vector, whose direction is perpendicular to the radius 
of the trajectory, therefore
the acceleration 
is directed toward the center of the circumference.
When smoke particles pass between the source of radiation and the detector the drop in radiation will be sufficient to tigger the alarm. <span />
At any crime scene, the two greatest challenges to the physical evidence are contamination and loss of continuity.
<h3>What is the meaning of physical evidence?</h3>
In evidence law, physical evidence (also called real evidence or material evidence) is any material object that plays some role in the matter that gave rise to the litigation, introduced as evidence in a judicial proceeding (such as a trial) to prove a fact in issue based on the object's physical characteristics.
The two types of evidence at crime scenes:
Biological evidence (e.g., blood, body fluids, hair and other tissues)
Latent print evidence (e.g., fingerprints, palm prints, footprints)
The biggest impediment to an investigation is the removal or loss of a piece of evidence from the scene of a crime.
Hence, at any crime scene, the two greatest challenges to the physical evidence are contamination and loss of continuity.
Learn more about the physical evidence here:
brainly.com/question/13505766
#SPJ1
