Cepheid variable stars are classified as either ____
a. Type A or Type B
b. Type I or Type II
c. Class A or Class B
d. Class I or Class II
e. Type C or Type R
b
You might also like to view...
Relative to its average speed in air, the average speed of a beam of light in glass is
A) more. B) the same. C) less.
John says that the value of the function cos[?(t + T) + ?], obtained one period T after time t, is greater than cos(?t + ?) by 2?. Larry says that it is greater by the addition of 1.00 to cos(?t + ?). Which one, if either, is correct?
a. John, because ?T = 2?. b. John, because ?T = 1 radian. c. Larry, because ?T = 2?. d. Larry, because ?T = 1 radian. e. Neither, because cos(? + 2?) = cos?.
A juggler throws two balls up to the same height so that they pass each other halfway up when A is rising and B is descending. Ignore air resistance and buoyant forces. Which statement is true of the two balls at that point?
a. There is an residual upward force from the hand on each ball. b. There is a greater residual force from the hand on A than there is on B. c. Only gravity acts on B but there is an additional residual force from the hand on A. d. There is an additional downwards force besides gravity on each ball. e. The only force acting on each ball is the gravitational force.
A chair is placed on a rug. Then a book is placed on the chair. The floor exerts a normal force
a. on all three. b. only on the book. c. only on the rug. d. upwards on the rug and downwards on the chair. e. only on the objects you have defined to be part of the system.