Answer:

Explanation:
The index of refraction is equal to the speed of light c in vacuum divided by its speed v in a substance, or
. For our case we want to use
, which for our values is equal to:

Which we will express with 3 significant figures (since a product or quotient must contain the same number of significant figures as the measurement with the <em>least</em> number of significant figures):

Answer:
180 miles/hr
Explanation:
15 min=1/4 hr
s= distance/time
s=45miles/1/4 hr
s=45miles x 4/1=180 miles/hr
Answer:
Conduction
Explanation:
"Conduction is the process by which heat energy is transmitted through collisions between neighboring atoms or molecules."
The heat in your hand melts that chocolate, making it conduction.
Answer:
Environmental Protection Agency (EPA)
Explanation:
In the United States of America, the agency which was established by US Congress and saddled with the responsibility of overseeing all aspects of pollution, environmental clean up, pesticide use, contamination, natural resources and hazardous waste spills is the Environmental Protection Agency (EPA). Also, EPA research solutions, policy development, and enforcement of regulations through the resource Conservation and Recovery Act.
The Environmental Protection Agency (EPA) is the governmental agency set up to ensure that various industries, factories and people comply with laws and regulations concerning the environment i.e it is an agency established to oversee and enforce environmental compliance by the people.
Hence, the Environmental Protection Agency (EPA) is saddled with the responsibility of enforcing federal and state laws related to environmental and natural resources.