A ball rolling down a hill has a constant acceleration of 3 m/s2 . If the ball's mass is 2.5 kg, what is the net force acting on the ball?
[Ques. 2] How will the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Laser Interferometer Space Antenna (LISA) observe gravitational waves?
a. They will detect vibrations in very long solid metal cylinders.
b. They will use laser light to detect tiny changes in the distance between mirrors placed far away from each other.
c. They will measure the force on precision masses at the ends of long tunnels from a large moving mass in the central building.
d. They will measure the changes in the attraction between two masses as one rotates past the other suspended from a thin metal wire.
e. They will measure changes in frequency of two masses swinging past each other.
[Ques. 3] A steel ball has a mass equal to 5 kilograms. What is the ball's weight?
[Ques. 4] Which of these is a likely source of strong gravity waves?
a. The Earth.
b. The Sun.
c. A supernova.
d. Nuclear fission.
e. Nuclear fusion in stars.
[Ques. 5] The sensitive dependence upon initial conditions of the evolution of some physical systems is a feature of __________.
Fill in the blank(s) with correct word
[Ques. 6] Which is one reason why gravitational waves have proved so hard to detect?
a. They probably have infinitesimally small wavelengths.
b. The strength of gravity is a tiny fraction of the strength of the electromagnetic force.
c. They would travel from many light years away at a very small fraction of the speed of light.
d. Their wavelengths would be infinitesimally small compared with the distance through space that they travel.
e. They are probably so different from other kinds of waves that it is difficult to theorize about how to detect them.
[Ques. 7] The major influence on the tides is due to __________.
Fill in the blank(s) with correct word
[Ques. 8] What is the color force?
a. The gravitational force mediated by gluons.
b. The force between quarks.
c. The force that ejects quarks from hadrons.
d. The force between electrons from the exchange of quarks.
e. The force that ejects quarks from gluons.
[Ques. 9] During the period of one day, the number of high tides at a given location is about __________.
Fill in the blank(s) with correct word
[Ques. 10] What is a gluon?
a. A flavor of quark.
b. The most newly discovered lepton.
c. A combination of three complementary quarks.
d. A particle exchanged by quarks.
e. A particle exchanged by electrons to give electrical repulsion.
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