Physics Chapter 4 quiz

When a projectile achieves escape speed from Earth, it _______.

outruns the influence of Earth's gravity, but is never beyond it

Earth satellites are typically more than 100-km high so as to mainly be above the Earth's

atmosphere

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

1/9

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

extends throughout the universe

Why doesn't the Moon fall toward Earth like apples do?

moon does fall but due to its tangential motion it also falls around Earth

An Earth satellite in an elliptical orbit travels fastest when it is An Earth satellite in an elliptical orbit travels fastest when it is

nearest the earth

Compared to the speed a satellite loses when traveling from nearest to farthest points from Earth, the speed gained when returning from farthest to nearest is

the same

Earth is gravitationally pulled toward _______.

the sun, Jupiter, mars

The speeds of the planets about the Sun depend on

their distances from the sun

Inside a freely-falling elevator your

weight is zero