All%20science%20is%20either%20physics%20or%20stamp%20collecting.%20%20-%20Ernest%20Rutherford%20(1871%20-%201937)%20Discoverer%20of%20the%20nucleus

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All science is either physics or stamp
collecting. - Ernest Rutherford (1871 -
1937)Discoverer of the nucleus
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A car goes around a banked curve that is icy
(frictionless).The centripetal force is
A absent (not needed) because of the banking B
the component of gravity acting toward the inside
of the curve C the component of the normal
force acting toward the inside of the curve D A
combination of BC
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A greasy (frictionless) hand pushes two blocks
against a vertical wall.There is static
friction, coefficient ?, between the blocks and
with the wall.You wish to find out the minimum
pushing force to keep the blocks from
slipping.Take out a pencil and paper, and draw
the required FBD(s).
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Fluid Resistance
C
A
B
Which curve could describe the (1D) velocity of a
block sliding down an inclined plane, as a
function of time?
Any answer accepted. B is Best.
Which curve could describe the (1D) velocity of a
skydiver, as a function of time?
C
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Assume the rate a car burns gas (in
gallons/minute) is proportional to the force the
engine applies to the road (through the tires, of
course.)How much faster do you burn gas at a
steady 80 mph vs at 40 mph? Assume all resistance
is air resistance. A You dont burn gas
because v is steadyB Same rate per minuteC
Twice as fast D Four times as fastE Sixteen
times as fast
Answer D, since resistance increases with the
square of velocity. Note your gas mileage would
be half at 80 mph as at 40 mph. Why?
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Forces acting on two particles are shown. The
forces are constant during the displacements
shown.
Which force does no work? A F1A B F2A C F1B D
F2B E They all do work
For which particle is the total work done by all
forces 0? Choose A, B, or C both0.
A
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Bonus Question If the forces shown are the only
forces acting on the particles, which particle
will change speed?
B will change its speed and velocity!