Your friend is trying to figure out which flap configuration makes a paper airplane fly the farthest. Which of the following is the independent variable?

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?

What sort of waves exhibit the doppler effect?

The items in the following list are all units of matter. which is the smallest unit that retains the properties of the matter? a.) atom b.) compound c.) electron d.) element