Physics 102 Motion Exercises Complete The Following Exercise

Phy 102 Motion Exercisescomplete The Following Exercises1 Jane Is

PHY-102: Motion Exercises Complete the following exercises. 1. Jane is collecting data for a ball rolling down a hill. She measures out a set of different distances and then proceeds to use a stopwatch to find the time it takes the ball to roll each distance. a. What is the independent variable in her experiment? The Ball b. What is the dependent variable in her experiment? The various distances c. Give one control variable for her experiment. Time 2. Consider an experiment where you drop an object. a. Briefly describe your proposed experiment. (Make sure it is controlled). b. What would be the independent variable for your experiment? c. What would be the dependent variable for your experiment? d. Give one control variable for your experiment. 3. Consider a freely falling object. a. What is the acceleration (in m/s2) after 5 seconds of fall? b. What is the acceleration (in m/s2) after 10 seconds of fall? c. What is the velocity (in m/s) after 5 seconds of fall? d. What is the velocity (in m/s) of 10 seconds of fall? 4. A sign is hung between two cables as illustrated below. If the sign weighs 350 N, what is the tension (in N) in each cable? 5. A construction worker on a high-rise building is on a platform suspended between two cables as illustrated below. The construction worker weighs 850 N, the plank weighs 450 N, and the tension in the left cable is 550 N. a. What is the tension (in N) in the right cable? b. Explain your answer. 6. Two forces of 50 N and 30 N, respectively, are acting on an object. Find the net force (in N) on the object if … a. the forces are acting in the same direction b. the forces are acting in opposite directions. 7. A box is pulled straight across the floor at a constant speed. It is pulled with a horizontal force of 48 N. a. Find the net force (in N) on the box. b. Find the force of friction (in N) from the floor on the box. c. The person pulling on the box stops pulling and the box comes to a rest. Find the force of friction (in N) on the box when at rest. 8. A bowling ball rolls 32 meters in 0.8 seconds. Find the average speed (in m/s) of the bowling ball in m/s. 9. A car accelerates from 3.5 m/s to 17 m/s in 4.5 seconds. Find the acceleration of the car in m/s2. 10. Rank the following from lowest to highest: a. The support force on you standing in an elevator at rest. b. The support force on you standing in an elevator accelerating upward. c. The support force on you standing in an elevator accelerating downward. 11. Describe the speed and acceleration of the ball released from the top of the track shown in the figure below. 12. Describe the speed and acceleration of the ball released from the top of the track shown in the figure below. 13. Describe the speed and acceleration of the ball released from the top of the track shown in the figure below. 14. You throw a ball upward with a speed of 14 m/s. What is the acceleration of the ball after it leaves your hand? Ignore air resistance and provide an explanation for your answer. 15. How would your answer to the previous question change if you take into account the effects of air resistance? 16. Describe the speed and acceleration of a person sky diving. Include in your explanation a description of the motion before the parachute is opened as well as a description of the motion after the parachute is opened. 17. A net force of 24 N is acting on a 4.0-kg object. Find the acceleration in m/s2. 18. A person pulls horizontally with a force of 64 N on a 14-kg box. There is a force of friction between the box and the floor of 36 N. Find the acceleration of the box in m/s2. Show your work. The remaining questions are multiple-choice questions: 19. One difference between a hypothesis and a theory is that a hypothesis A. is a guess that has not been well tested, whereas a theory is a synthesis of well-tested guesses. B. is testable, whereas a theory is not testable. C. can be revised, whereas a theory cannot be revised. D. is not testable, whereas a theory is testable. 20. A car starts from rest and reached a speed of 24 m/s in 6 seconds. What is the acceleration of the car? A. 144 m B. 6 m/s2 C. 4 m/s2 D. 10 m/s2 E. 0 m/s. Which of the following forces is NOT a contact force? A. Friction force B. Support force C. Force of gravity D. Tension force 22. If you pull horizontally on a desk with a force of 150 N and the desk doesn't move, the friction force must be 150 N. Now if you pull with 250 N so the desk slides at constant velocity, the friction force is A. more than 150 N, but less than 250 N. B. 250 N. C. more than 250. 23. Suppose a particle is accelerated through space by a constant 10 N force. Suddenly the particle encounters a second force of 10 N in a direction opposite to that of the first force. The particle A. is brought to a rapid halt. B. theoretically accelerates to speeds approaching the speed of light. C. continues at the speed it had when it encountered the second force. D. gradually slows down to a halt. 24. Newton's First Law of Motion applies to A. objects at rest only. B. moving objects only. C. both moving and nonmoving objects. 25. A freely falling object starts from rest. After falling for 2 seconds, it will have a speed of about A. 5 m/s B. 10 m/s C. 20 m/s D. 40 m/s 26. Suppose an object is in free fall. Each second the object falls A. the same distance as in the second before. B. a larger distance than in the second before. C. with the same instantaneous speed. D. with the same average speed.

Paper For Above instruction

The set of physics exercises provided covers fundamental concepts in motion, force, and kinematics, essential for understanding classical mechanics. This comprehensive analysis will address each question systematically, elaborating on the principles involved, calculations where applicable, and real-world applications. The goal is to synthesize these problems into a coherent understanding of the principles governing motion and forces.

Analysis of Experimental Variables in Motion

In Jane's experiment involving a ball rolling down a hill, the independent variable is the factor she deliberately changes—in this case, the distance the ball travels, which directly influences the time measured. The dependent variable is the outcome affected by the independent variable—in her experiment, it is the time taken for the ball to roll each distance. Control variables are aspects kept constant to ensure a fair test; here, variables such as the surface texture, ball mass, and initial velocity could be controlled to isolate the effect of distance on timing. This setup exemplifies basic experimental design principles in physics experiments.

Free Fall and Acceleration

For a freely falling object near Earth's surface, the acceleration due to gravity remains constant at approximately 9.8 m/s^2, regardless of the fall duration. Therefore, after 5 or 10 seconds, the acceleration remains 9.8 m/s^2. The velocity after a certain time in free fall can be calculated using v = g t; thus, after 5 seconds, v = 9.8 5 = 49 m/s, and after 10 seconds, v = 9.8 * 10 = 98 m/s (assuming no air resistance).

Tension in Cables and Forces in Structures

When a sign weighs 350 N and is suspended between two cables, the tension in each cable depends on the angle of the cables and the weight distribution. Assuming symmetrical cables and angles, each cable bears half the weight, resulting in a tension of approximately 350 N / 2 = 175 N, adjusted for cable angles using trigonometric considerations.

Similarly, a platform suspended between two cables supporting a worker and a plank involves resolving forces vertically. The total weight (worker plus plank) equals 1,300 N. Given one cable's tension, the other can be determined via equilibrium equations, considering the angles and directions.

Forces and Motion

Net force calculations involve vector addition. When forces act in the same direction, the net force equals the sum of magnitudes, e.g., 50 N + 30 N = 80 N. When forces oppose each other, the net force equals their difference, e.g., 50 N - 30 N = 20 N.

From Newton's Second Law, F = ma, the acceleration is derived by dividing the net force by the mass of the object. For example, for a 4.0 kg object with a net force of 24 N, acceleration a = 24 N / 4.0 kg = 6 m/s^2.

Friction forces oppose motion, and their magnitude equals the coefficient of friction times the normal force; in simple cases, friction matches the applied force when moving at constant speed.

Velocity, Speed, and Acceleration Calculations

Average speed is calculated as total distance divided by total time; thus, a bowling ball covering 32 meters in 0.8 seconds has an average speed of 40 m/s. Acceleration is the change in velocity over time, so for a car accelerating from 3.5 m/s to 17 m/s over 4.5 seconds, acceleration a = (17 - 3.5) / 4.5 ≈ 2.78 m/s^2.

In ranking forces such as the support force in an elevator scenario, the support force increases with upward acceleration, surpassing the weight during upward acceleration and decreasing below during downward acceleration.

Projectile Motion and Air Resistance

When a ball is thrown upward at 14 m/s, ignoring air resistance, the acceleration immediately after leaving the hand is due to gravity, -9.8 m/s^2—constant downward acceleration. If air resistance is considered, the acceleration's magnitude decreases slightly during ascent, and the net acceleration reduces as drag opposes the motion, impacting velocity and acceleration at each point.

Skydiving Motion and Particles in Space

Skydivers accelerate downward due to gravity, but as their speed increases, air drag increases until it balances gravity, resulting in terminal velocity—no further acceleration. When the parachute opens, air resistance dramatically increases, decelerating the diver, eventually reaching a new, lower terminal velocity. This process exemplifies how forces and air resistance influence motion significantly.

Force, Acceleration, and Newton’s Laws

Applying Newton's Second Law, for a net force of 24 N on a 4.0 kg mass, the acceleration is a = F/m = 24/4 = 6 m/s^2. The laws govern all motion aspects discussed, including the response of objects to applied forces, the concept of inertia, and the proportional relationship between force, mass, and acceleration.

Horizontal pulling forces involve friction opposing motion. When pulling with a force of 64 N on a 14 kg box with frictional force of 36 N, the net force is 64 - 36 = 28 N, leading to an acceleration a = 28 / 14 = 2 m/s^2.

Theoretical and Conceptual Questions

Hypotheses are testable and based on initial observations, whereas theories are comprehensive explanations supported by extensive evidence. Car acceleration derived from velocity change over time yields 4 m/s^2, aligning with the formula a = Δv/Δt. Contact forces, like friction and tension, involve direct physical contact, whereas gravity is a non-contact force acting at a distance.

Friction force adjusts to match applied horizontal forces when the surface is at constant speed, but once movement begins, friction is more than or less than specific applied forces depending on the scenario, mainly governed by the coefficient of friction and normal force.

In space, with no external forces, a particle accelerated by a 10 N force, encountering an opposite 10 N force, would experience a net zero force; thus, it would continue at a constant velocity according to Newton's First Law. When an object is in free fall, it accelerates uniformly at 9.8 m/s^2, and the distance fallen each second increases cumulatively, following quadratic growth (d = 0.5 g t^2).

Conclusion

This comprehensive review of these physics exercises encapsulates core principles of motion, forces, and energy, providing a solid foundation for further exploration. Practical applications of these concepts are vital in engineering, sports analytics, safety engineering, and space exploration.

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