Alpha particles cannot penetrate deeply into solids because they

Where do humans get their energy from?

In what ways do observed extrasolar planetary systems differ from our own solar system?

Which uses the refractive properties of light to separate it into its different wavelengths? A. white light from the surface of a mirror B. colored light as it travels from a solid medium to a liquid medium C.

Where do earthquake waves originate from? select one: a. earth's inner core b. the epicenter c. the focus d. the core-mantle boundary?

What is speed? A. Distance (miles or meters) B. Time (hours or seconds) C. Time per distance (hours per mile or seconds per meter) D. Distance per time (miles per hour or meters per second)

Which of the following best characterizes the free energy change ΔG for an endothermic reaction under physiological conditions? A. The sign of ΔG is positive B. The sign of ΔG is zero C. The sign of ΔG is negative D.

In a recent hockey game, one player (m=100kg) was moving at a velocity of 8 m/s when he ran into another player (m=300kg) who was at rest (v=0m/s). After the collision, the two players were stuck together (moving with the same velocity).

In a laser, electrical energy is changed to light energy, and a small amount of the energy is wasted as heat. Describe the total amount of the heat in the system (using the conservation of energy).

What is the name for a star and planets held together by gravity? A. solar system B. galaxy C. black hole D. supernova

When a car turns a corner on a level road, which force provides the necessary centripetal acceleration? 1) gravity 2) normal force 3) air resistance 4) tension 5) friction