The star delta goes supernova. one year later and 2 ly away, as measured by astronomers in the galaxy, star epsilon explodes. let the explosion of delta be at xd=0 and td=0 . the explosions are observed by three spaceships cruising through the galaxy in the direction from delta to epsilon at velocities v1=0.3c, v2=0.5c and v3=0.7c.

1. what are the times of the two explosions as measured by scientists on each of the three spaceships? the times are given in years.
2.does one spaceship find that the explosions are simultaneous? if so, which one?
3. does one spaceship find that epsilon explodes before delta? if so, which one?
4. do your answers to parts b and c violate the idea of causality?

Use the data provided to calculate the gravitational potential energy of each cylinder mass. round your answers to the nearest tenth. 3 kg: kj 6 kg: kj 9 kg: kj

Amarble, a bowling ball, a basketball, and a baseball are rolling across the floor at 10 m/s. which one has the greatest kinetic energy? the marble the bowling ball the basketball the baseball

What is the relationship between atmospheric pressure and the density of gas particles in an area of increasing pressure? (2 points) as air pressure in an area increases, the density of the gas particles in that area decreases. as air pressure in an area increases, the density of the gas particles in that area increases. as air pressure in an area increases, the density of the gas particles in that area remains constant. as air pressure in an area increases, the density of the gas particles in that area increases and decreases in an alternating pattern. 3. which of the following correctly describes a way in which earth's atmosphere interacts with the geosphere? (2 points) it contains gases that living organisms breathe. it contains gases that trap incoming solar radiation. it provides a medium for cycles that provide nutrients to living organisms. it provides a medium for water to move between earth's surface and the air. 4. which of the following is considered a drawback to using wind energy as a source of power? (2 points) wind energy is nonrenewable. wind energy produces large amounts of air pollution. wind turbines can kill birds that fly through the rotors. wind turbines are built too close to major population centers. 5. a meteorologist predicts that the weather in a region will soon change from clear skies to probable thunderstorms. prior to making this prediction, what did the meteorologist most likely observe on a barometer? (2 points) the barometer fell slightly. the barometer fell substantially. the barometer rose slightly. the barometer rose substantially. 6. which of the following do meteorologists not typically use weather balloons to record? (2 points) atmospheric pressure cloud types humidity temperature 7. during which step in the can crush lab did water vapor force air from the can? (2 points) the can was filled nearly to the top with water. the can was placed on the hot stove top burner for several minutes. the can was removed from the hot stove top burner. the can was placed upside-down in the water-filled pan.