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1. If you know the acceleration a of a point P in straight-line motion as a function of time, i.e. art), but have
no other information, you can't determine the position and velocity of P as functions of time. Why not?
(5%)
2. If the tangential component of the total force on an object is constant, what do you know about the work
done as the object moves a given distance along its path? (5%)
3. The 30 lb weight is released from rest with the spring (k A =30 lbl ft , k B =15lb 1ft) unstretched (Figure
3).
(a) How far does the weight fall before rebounding?
(b) What maximum velocity does it attain? (20%)
Figure 3
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4. The combined mass of the motorcycle and rider is 160 kg. The motorcycle starts from rest at t = 0 and
moves along a circular track with a 400 m radius (Figure 4). The tangential component of acceleration of
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the motorcycle as a function of time is at=2+0.2t ml s2. The coefficient of static friction between the tires
and track is ,us =0.8. How long after it starts does the motorcycle reach the limit of adhesion, which
means that its tires are on the verge of slipping? How fast is the motorcycle moving when that occurs?
(20%)
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Figure 4
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5. The 10-kg rodAB shown in Fig. 5 is confined so that its ends move in the horizontal and vertical slots. The
AB when
(25%)
e = 0° . Determined the angular velocity of
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spring has a stiffness of k = 800 N/m and is unstretched when
e = 0°, if the rod is released from rest when e = 30°. Neglect the mass of the slider blocks.
Figure 5
=800N/m
6. A 4-kg block is suspended from a spring that has a stiffness of k = 600 N/m. The block is drawn downward
50 mm from the equilibrium position and released from rest when t = O. If the support moves with an
impresses displacement of 0 = (10 sin 4t) mm, where t is in seconds, determine the equation that
describes the vertical motion of the block. Assume positive displacement is downward. (25%)