Teaching Modern Physics - QuarkNet - Fermilab

d.) energy / a silicon detector and a magnet / momentum / a calorimeter
18. When objects collide:
a.) the initial velocity of the objects must equal the final velocity of the objects.
b.) the initial momenta of the objects is greater than the final momenta of the objects.
c.) the initial momenta of the objects is less than the final momenta of the objects.
d.) the initial momenta of the objects must equal the final momenta of the objects.
19. A 0.5-kg puck moving with a speed of 3 m/s collides with a stationary 2-kg puck. After
the collision, the 2-kg puck moves off in the same direction as the 0.5-kg puck was
moving before the collision with a speed of 1 m/s. What is the final velocity of the 0.5-kg
puck?
a.) 0 m/s b.) 1 m/s in
the same direction
154
c.) 1 m/s in the
opposite direction
A p + and a π o were created from the decay of an unknown particle. Using this
information and the questions below, identify the unknown particle.
20. What was the energy of that unknown particle if the p + has an energy of 0.973 GeV and
the π o has an energy of 0.325 GeV?
a.) 0.32 GeV
b.) 0.648 GeV
c.) 1.30 GeV
d.) 2.99 GeV
21. What was the momentum of the unknown particle that decayed if the p + has a momentum
of 0.257 GeV/c and initially travels at an angle of 21.5 degrees and the π o has a
momentum of 0.295 GeV/c and initially travels at an angle of –18.7 degrees?
a.) 0.257 GeV/c (cos 21.5 0 ) + 0.295 GeV/c (cos 18.7 0 )
b.) 0.257 GeV/c (sin 21.5 0 ) + 0.295 GeV/c (sin 18.7 0 )
c.) 0.257 GeV/c (cos 21.5 0 ) + 0.295 GeV/c (sin 18.7 0 )
d.) 0.257 GeV/c (sin 21.5 0 ) + 0.295 GeV/c (cos 18.7 0 )
22. Using your results from questions 20 and 21, compute the rest mass and identify the
particle that decayed.