Conservation laws can be used even when the details of what is occurring inside a system aren't known.
Indicate whether the statement is true or false
[Ques. 2] Which force would not be explained in a grand unified theory, but would require a theory of everything?
a. The weak force.
b. The strong (or color) force.
c. The electromagnetic force.
d. The gravitational force.
e. The electroweak force.
[Ques. 3] A satellite orbits the earth at a distance of 10,000 miles from the earth's center. At this distance the force of gravity on the satellite is 90 lbs. (a) What would the force on the satellite be if the distance were 5,000 miles instead? (b) At what distance from the earth's center would the force on the same satellite be 10 lbs?
[Ques. 4] Which of these is NOT true about the standard model of elementary particles currently accepted by most physicists?
a. It seems to explain every relevant experiment that can be done.
b. It combines two of the four basic forces into an electroweak interaction.
c. It combines the electroweak interaction with the color interaction.
d. It connects the color theory to the strong force.
e. It calls for mathematical calculations that are currently impossible.
[Ques. 5] A child on a merry-go-round is moving with speed 4 m/s in a circle with radius 2 m. If the child's mass is 30 kg, what is the centripetal force?
[Ques. 6] There are currently considered to be _________ basic building blocks for elementary particles and _________ different forces in the universe.
a. 4 / 25
b. 8 / 4
c. 4 / 8
d. 6 / 4
e. 25 / 4
[Ques. 7] A certain speed boat weighs 4,900 N. It can accelerate from 0 to 20 m/s in 5 seconds. (a) What is the mass of the boat? (b) What is the acceleration? (c) How large is the net force acting on the boat?
[Ques. 8] Which of these is a strong circumstantial indication that gravity waves exist?
a. A supernova occurs on an average once every 15 years in the Galaxy.
b. Objects fall down on Earth, not up.
c. Orbiting neutron stars lose speed at a rate that fits a gravity wave theory.
d. The trajectory of electrons ejected from nuclei fits a gravity wave theory.
e. The slight changes in Earth's motion, requiring an extra leap second added onto the year 2005.
[Ques. 9] A 3,000 kg truck experiences a net force of 2,000 N. What is its acceleration?
[Ques. 10] This illustration shows the orbits of the three satellites that will compose the Laser Interferometer Space Antenna (LISA). What gravitational wave frequencies will LISA be sensitive to?
a. 0.0001 to 1 hertz to observe gravitational waves from binary systems and black holes.
b. 1 to 10 hertz to observe gravitational waves from binary systems and black holes.
c. 10 to 1000 hertz to observe gravitational waves from supernovae.
d. 0.0001 Hertz to 1 hertz to observe gravitational waves of planets moving around stars.
e. 0.0001 Hertz to 1 hertz to observe gravitational waves of moons moving around planets.
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