Physics I Practice Problems For Dummies (+ Free Online Practice). Dummies Consumer

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СКАЧАТЬ Recognizing that the horizontal component of acceleration is zero for freely falling objects

Getting to Know Vectors

      71–72

       71. How many numbers are required to specify a two-dimensional vector?

       72. Marcus drives 45 kilometers at a bearing of 11 degrees north of west. Which of the underlined words or phrases represents the magnitude of a vector?

Adding and Subtracting Vectors

      73–75

       73. Vector U points west, and vector V points north. In which direction does the resultant vector point?

       74. If vectors A, B, and C all point to the right, and their lengths are 3 centimeters, 5 centimeters, and 2 centimeters, how many centimeters long is the resultant vector formed by adding the three vectors together?

       75. Initially facing a flagpole, Jake turns to his left and walks 12 meters forward. He then turns completely around and walks 14 meters in the opposite direction. How many meters farther away from the flagpole would Jake have ended had he started his journey by turning to the right and walking 14 meters and then turning completely around and walking the final 12 meters?

Adding Vectors and Subtracting Vectors on the Grid

      76–79

       76. If

and , what is the value of ?

       77. If

, what is the value of ?

       78. Given that

and , calculate .

       79. Given the three vectors

, , and , solve for D if .

Breaking Vectors into Components

      80–83

       80. Vector A has a magnitude of 28 centimeters and points at an angle 80 degrees relative to the x-axis. What is the value of

? Round your answer to the nearest tenth of a centimeter.

       81. Vector C has a length of 8 meters and points 40 degrees below the x-axis. What is the vertical component of C, rounded to the nearest tenth of a meter?

       82. Jeffrey drags a box 15 meters across the floor by pulling it with a rope. He exerts a force of 150 newtons at an angle of 35 degrees above the horizontal. If work is the product of the distance traveled times the component of the force in the direction of motion, how much work does Jeffrey do on the box? Round to the nearest ten newton-meters.

       83. Three forces pull on a chair with magnitudes of 100, 60, and 140, at angles of 20 degrees, 80 degrees, and 150 degrees to the positive x-axis, respectively. What is the component form of the resultant force on the chair? Round your answer to the nearest whole number.

Reassembling a Vector from Its Components

      84–87

       84. What are the magnitude and direction of the vector

? Round your answers to the nearest tenth place and give your angle (direction) in units of degrees.

       85. Given vectors

and , what angle would vector C make with the x-axis if ? Round your answer to the nearest tenth of a degree.

       86. If you walk 12 paces north, 11 paces east, 6 paces south, and 20 paces west, what is the magnitude (in paces) and direction (in degrees relative to the positive x-axis) of the resultant vector formed from the four individual vectors? Round your results to the nearest integer.

       87. After a lengthy car ride from a deserted airfield to Seneca Airport, Candace finds herself 250 kilometers north and 100 kilometers west of the airfield. At Seneca, Candace boards a small aircraft that flies an unknown distance in a southwesterly direction and lands at Westsmith Airport. The next day, Candace flies directly from Westsmith to the airfield from which she started her journey. If the flight from Westsmith was 300 kilometers in distance and flew in a direction 15 degrees south of east, how many kilometers was Candace’s flight from Seneca to Westsmith? Round your answer to the nearest integer.

Describing Displacement, Velocity, and Acceleration in Two Dimensions

      88–96

       88. Hans drives 70 degrees north of east at a speed of 50 meters per second. How fast is Hans traveling northward? Round your answer to the nearest integer.

       89. If you walk 25 meters in a direction 30 degrees north of west and then 15 meters in a direction 30 degrees north of east, how many meters did you walk in the north-south direction?

       90. Jake wants to reach a postal bin at the opposite corner of a rectangular parking lot. It’s located 34 meters away in a direction 70 degrees north of east. Unfortunately, the lot’s concrete was recently resurfaced and is still wet, meaning that Jake has to walk around the lot’s edges to reach the bin. How many meters does he have to walk? Round your answer to the nearest whole meter.

       91. If

, use the following information to determine the components of D. Use ordered-pair notation rounded to the nearest tenth of a meter for your answer. (All angles are measured relative to the x-axis.)

      A: 45 meters at 20 degrees

      B: 18 meters at 65 degrees

      C: 32 meters at –20 degrees

       92. To walk from the corner of Broadway and Park Place to the corner of Church and Barkley in Central City, a person must walk 150 meters west and then 50 meters south. How many meters shorter would a direct route be? Round your answer to the nearest meter.

       93. If Jimmy walks 5 meters east and then 5 meters south, what angle does the resultant СКАЧАТЬ