If two particles have equal momenta, are their kinetic energies equal（）
A. yes, always
B. no, never
C. no, except when their speeds are the same
D. yes, as long as they move along parallel lines
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Object 1 has twice the mass of Object 2. Both objects have the same kinetic energy. Which of the following statements is true（）
A. Both objects can have the same magnitude of momentum
B. Object 1 has a momentum of greater magnitude than Object 2
C. The magnitude of the momentum of Object 2 is four times that of Object 1
D. All the statements are false
E. All the statements are true
A valid unit for momentum is which of the following（）
A. kg∙m/s^2
B. kg/m^2
C. kg∙m/s
D. N∙m
E. None of the others
Three satellites are launched into space connected together. Once in deep space, an explosive charge separates the three satellites and they move apart. The satellites each have different masses with
A. The one with mass m1 receives the greatest impulse
B. The one with mass m3 receives the greatest impulse
C. The all must receive equal impulses
D. Although one or more of the above statements could be true in special cases, they are not always true
A high-diver of mass 70 kg jumps off a board 10 m above the water. If, 1.0 s after entering the water his downward motion is stopped, what average upward force did the water exert（）
A. 100 N
B. 686 N
C. 980 N
D. No answer is correct
E. 0 N
F. 10 N
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