Physics Chapter 11 Assessment

The moon falls toward Earth in the sense that it falls

beneath the straight-line path it would take without gravity

A black hole is

simply a collapsed star

When an astronaut in orbit is weightless, he or she is

still in the pull of Earth's gravity

Planets remain in orbit while falling around the sun due to their

tangential velocities

Newton did not discover gravity, for early humans discovered it whenever they fell. What Newton did discover is that gravity

extends throughout the universe

The highest ocean tides occur when the Earth and moon are

lined up with the sun

Compared to the gravitational field of Earth at its surface, Earth's gravitational field at a distance three times as far from Earth's center is about

one ninth as much

Consider a space probe three times as far from Earth's center. Compared at Earth's surface, its gravitational attraction to Earth at this distance is about

one ninth as much (3 squared under one)

Newton determined that the pull of Earth's gravity caused both apples and

the moon to fall toward Earth

Compared to the gravitational field of Earth at its surface, Earth's gravitational field at Earth's center is

zero