Ch4_2
New Problems
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Make sure to calculate your answers in SI units unless specified otherwise .
1) Two blocks are connected via a string that runs over a pulley (
see sheet 19
, replace the 30
degrees
by 0
degrees
). The
kg
block slides on a frictionless horizontal plane. The other block with a mass of
kg
is suspended from the string. What is the tension of the string when the blocks are released
(see sheet 21
, eliminate
a
)
?
2) An object moves with constant velocity of
m/s
(both direction and magnitude are constant ). A force of
N
directed west and a second force directed east act on the object. What is the magnitude of the second force
(see sheet 6,30)
?
3) A
kg
block slides with constant velocity on a horizontal plane. The coefficient of friction is . The block is pushed by a force which is parallel to the plane. How large is this force
(see sheet 6,30 and 24,29,29')
? Indicate with a negative (positive) sign whether the direction of this force can (cannot) be obtained from the direction in which the block is sliding.
4) A block slides down an inclined plane with constant velocity. The angle of inclination is
degrees
with respect to the horizontal. What is the coefficient of friction
(see sheet 6,30 and 27,28)
? Indicate with a positive (negative) sign whether you can (cannot) calculate the normal force from the information given.
5) A
N
weight is suspended from two strings which both make a
degree
angle with the vertical
(see sheet 31
; watch out! Place the angle correctly
)
. What is the tension in each string
(see sheet 32,33
but simpler
)
. Indicate with a negative (positive) sign whether the horizontal components of the tensions in the strings cancel (do not cancel) each other.
6) An object at rest at the center of a square (all sides with equal length) has 4 forces acting on it, each directed along lines from a different corner of the square toward the center. The two forces acting from the lower left and lower right corners are directed toward the center and have
N
each. What is the magnitude of the two remaining forces which leaves the object at rest
(see sheet 36,36')
? Indicate with a positive (negative) sign whether your answer is (not) the same if the object moves with constant velocity.
Once you have submitted your answers for grading by clicking the grade button, you
cannot resubmit answers
for the same Problem Set--you must use the 'New Problems' button first.