An umbrella tends to move upward on a windy day because
a. buoyancy increases with increasing wind speed
b. air gets trapped under the umbrella and pushes it up
c. the wind pushes it up
d. a low-pressure area is created on top of the umbrella
e. all of the above

30 points - when can a theory be modified if a new type of technology allows for new observations that raise new questions? a. immediately, while the questions about the theory are being asked b. after new hypotheses related to the theory are tested in experiments c. only after the new observations disprove all parts of the theory d. while scientists begin to think about how the theory could improve

What is the rate of change in a objects position?

In a system with only a single force acting upon a body, what is the relationship between the change in kinetic energy and the work done by the force? answers: work is equal to the change in kinetic energy.work depends on the square of the change in potential energy.work is equal to the negative of the change in kinetic energy.work is equal to the square of the change in kinetic energy