Why are scientific theories modified, but seldom discarded?

A car traveling at 25 m/s starts to decelerate steadily. It comes to a complete stop in 12 seconds. What is its acceleration?

Analyze what happens to the air pressure as you increase in the altitude. How might this affect athletes who compete at higher altitudes?

An uncharged conductor has a hollow cavity inside of it. Within this cavity there is a charge of + 10 µC that does not touch the conductor. There are no other charges in the vicinity. Which statement about this conductor is true?

Which of the following elements is considered to be a non-metal?

Which statement is true about two isotopes of the same element? A. They have the same mass number. B. They have different numbers of protons. C. They have different locations on the periodic table. D. They have different numbers of neutrons.

Describe the factors that form deep currents

A comet is cruising through the solar system at a speed of 50000 kilometers per hour for 4 hours time. What is the total distance traveled by the comet during this time in kilometers, miles, and light years?

A gas in a closed container is heated with 12J of energy, causing the lid of the container to rise 3m with 5N of force. What is the total change in energy?

What are illuminated objects?

During one year a population of blue jays has zero population growth. which must be true about the blue jay population at the end of the year compared to the beginning of the year?