Physics 201  MWF10:20   Fall 1994 (Ford)
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Exam I   Chapts. 1-5 in SZY College Physics
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Show all your work. Partial credit will be given if earned. Write your 
answers in the blanks provided.
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(14 pts) 1. Vectors <b>A</b> and <b>B</b> are given in the sketch.
Vector <b>A</b> has magnitude 2.0 m and vector <b>B</b> has magnitude 8.0 m.
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<img src="fig/i941.gif">
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a) What are the <i>x</i> and <i>y</i> components of the vector <b>B</b>?
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Ans. <i>B<sub>x</sub></i> = _____________________
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<i>B<sub>y</sub></i> = _________________________
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b) What are the magnitude and direction (angle <img src="greek/theta.gif">
measured counterclockwise from the +<i>x</i>-axis)
of the vector <b>C</b> that is
the sum of the vectors <b>A</b> and <b>B</b> shown in the sketch 
(<b>C</b> = <b>A</b> +<b>B</b>)?
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Ans. <i>C</i> = _________________________
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<img src="greek/theta.gif"> = __________________
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(20 pts) 2. A car and a truck are traveling in the same direction on a straight
section of an Interstate Highway. At one instant the truck and car are
alongside each other; at this instant the truck has a speed of
15.0 m/s and the car has a speed of 6.0 m/s.
The truck continues to travel with constant speed; the car has an acceleration
of 0.2 m/s<sup>2</sup>. Initially the truck moves ahead of the car but then the
car catches up.
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a) What distance does the car travel before it catches up with the truck?
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Ans. _______________________________
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b) What is the speed of the car when it overtakes the truck?
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Ans. _________________________
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(22 pts) 3. A rock is thrown with a velocity of magnitude 15 m/s 
and at an angle of 37&#176 above the horizontal from the roof of a building.
The rock is observed to strike the ground 5.0 s after being thrown. Calculate
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a) the height of the building;
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Ans. ___________________________
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b) the horizontal distance <i>R</i> from the base of the building to where the
rock hits the ground.
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Ans. _______________________
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c) the magnitude and direction (angle relative to the horizontal)
of the velocity of the ball just before it strikes the ground.
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Ans. <img src="greek/
theta.gif"> = ________________________
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<i>v</i> = _____________________
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(22 pts) 4. An object of mass <i>m</i> is suspended using three ropes <i>A</i>, 
<i>B</i>, and <i>C</i>, as shown in the sketch. Rope <i>A</i> is horizontal,
rope <i>B</i> is vertical and is attached to the object, and rope <i>C</i>
makes an angle of 53&#176  with the ceiling. All three ropes have negligible
mass. The tension in the horizontal rope, rope <i>A</i>, is observed
to be 40 N.
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<img src="fig/i944.gif">
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a) What is the tension in the rope <i>C</i>?
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Ans. ____________________________
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b) What is the mass <i>m</i> of the object?
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Ans. _________________________________
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(22 pts) 5. Block <i>A</i> has mass 4.0 kg and is on a horizontal tabletop.
The coefficient of
kinetic friction between the block and the tabletop is &#181<sub>k</sub> = 0.4.
Block <i>A</i> is connected by a massless rope that passes over a massless,
frictionless pulley to a hanging block, block <i>B</i>, that has mass 6.0 kg.
A horizontal force <i>P</i> is applied to block <i>A</i> and starting from rest
block <i>A</i> moves 0.90 m to the left in 3.0 s.
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<img src="fig/i945.gif">
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a) What is the magnitude of the acceleration of block <i>A</i>?
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Ans. ______________________
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b) What is the tension in the rope that connects the two blocks?
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Ans. ___________________
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c) What is the magnitude of the force <i>P</i>?
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Ans. __________________________