Which characteristic should a good scientific question have? A) It should lead to a hypothesis that is not testable. B) it should have a very broad focus with many variables. C) it should repeat a question that the researcher has had before. D it should be based on observations instead of just imagination.

When an object is heated it contracts. a. true b. false

As part of your daily workout, you lie on your back and push with your feet against a platform attached to two stiff springs arranged side by side so that they are parallel to each other. when you push the platform, you compress the springs. you do an amount of work of 79.0 j when you compress the springs a distance of 0.230 m from their uncompressed length. (a) what magnitude of force must you apply to hold the platform in this position? (b)how much additional work must you do to move the platform a distance 0.230 m farther? (c) what maximum force must you apply to move the platform a distance 0.230 m farther?

In which of the following is positive work done by a person on a suitcase