The greenhouse effect is a result of

a. absorption and radiation of energy in the hydrosphere.
b. reflection of solar energy by cloud cover.
c. aerosolization of dust and gases produced by volcanoes.
d. absorption and radiation of energy in the atmosphere.

What do butterflies have on their feet which allows them to sense different strengths and types of nectar? a.mechanoreceptors b.acoustic receptors c.substratum receptors d.chemoreceptors

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?

(a) if the pressure in gas is doubled while its volume is held constant, by what factor do (i) vrms and (ii) change? (b) is it possible to boil water at room temperature (20oc) without heating it? explain.