When was it first known that Earth was spherical in shape?

A. It was always known to be spherical.
B. only after Galileo used a telescope to study other planets
C. at the beginning of the Renaissance
D. at the time of the Greeks
E. only recently within the last hundred years


Answer: D

Physics & Space Science

You might also like to view...

The atomic mass system is based upon

A. the mass of uranium-238, since it is the heaviest element occurring in nature. B. the mass of the neutron. C. the mass of carbon-12, a very common isotope of carbon. D. the mass of liquid water.

Physics & Space Science

A ?- decay occurs in an unstable nucleus when

A) a proton is converted to an electron by the strong force. B) a proton is converted to a neutron by the strong force. C) a neutron is converted to a proton by the weak force. D) a neutron is converted to an alpha particle by the weak force. E) a neutron is converted to a beta particle by the weak force.

Physics & Space Science

The only two forces acting on a body have magnitudes of 20 N and 35 N and directions that differ by 80°. The resulting acceleration has a magnitude of 20 m/s2 . What is the mass of the body?

a. 2.4 kg b. 2.2 kg c. 2.7 kg d. 3.1 kg e. 1.5 kg

Physics & Space Science

What characteristic of neutrinos other than their flavor is essential to the theory of neutron oscillation?

a. Their three different wavelengths. b. Their three different frequencies. c. Their three different electric charges (+, 0, and -). d. Their three different masses. e. Their three different colors.

Physics & Space Science