Since invasive species did not co-evolve with the other species in the ecosystem where they were introduced . a.
they can unbalance the ecosystem
b.
they are considered a serious environmental problem
c.
they lack natural predators to help control their population
d.
all of the above

The astronauts on the space shuttle flights experienced an acceleration of 29 m/s2 (about 3 "g's") during lift-off. what upward force must the astronaut's seat apply to the astronaut in order to cause this acceleration? assume the astronaut's mass is 70 kg, and compute this force when the acceleration is near the earth's surface so their weight equals latex: mg m g .