0625/23/M/J/17 7
The diagram shows a man holding a sack and barrow stationary. He applies a vertical force to
the handle.
The centre of mass and the weight of the sack and barrow are shown. The wheel acts as a pivot.
force
exerted
by man
centre of mass
of sack and barrow
20 cm
80 cm
15 cm 45 cm
weight of
sack and barrow
200N
What is the magnitude of the vertical force exerted by the man?

Quantum mechanics applies to subatomic, atomic, nanometer-size, and micrometer-size systems. nanometer, micrometer, and kilometer-size systems. atomic, nanometer-size, and micrometer-size systems. subatomic, atomic, and nanometer-size systems.

Match each vocabulary term to its definition. 1. electrons neutral subatomic particles found in the nucleus of the atom 2. neutron lowest energy position of an electron in an atom 3. photon the path of an electron around the nucleus of an atom 4. ground state negatively charged, subatomic particles 5. protons packet of energy of specific size 6. element substance with only one type of atom 7. orbital positively charged, subatomic particles found in the nucleus of the atom

The bar of prob. 5/82 is repeated here. the ends of the 0.4-m bar remain in contact with their re- spective support surfaces. end b has a velocity of 0.5 m/s and an acceleration of 0.3 m/s2 in the di- rections shown. determine the angular accelera- tion of the bar and the acceleration of end a.