Problem 1RQ Problem 2RQ: Review Question 8.2 Give an example of a situation in which (a) a torque produced by a force is zero... Problem 3RQ: Review Question 8.3 You read the following sentence in a book: In problem solving, put the axis at... Problem 4RQ Problem 5RQ: Review Question 8.5 You are trying to hold a heavy dumbbell in one hand so that your arm is... Problem 6RQ: Review Question 8.6 Why is a ball hanging by a thread in stable equilibrium, while a pencil balanced... Problem 1MCQ: A falling leaf usually flutters while falling. However, we have learned that the force that Earth... Problem 2MCQ Problem 3MCQ: A hammock is tied with ropes between two trees. A person lies in it Under what circumstances are its... Problem 4MCQ Problem 5MCQ: 5. A physics textbook lies on top of a chemistry book, which rests on a table. Which force diagram... Problem 6MCQ: What does it mean if the torque of a force is positive? a. The object exerting the force is on the... Problem 7MCQ Problem 8MCQ: 8. Why do you tilt your body forward when hiking with a heavy backpack?
a. The backpack pushes you... Problem 9MCQ: 9. What does it mean if the torque of a 10-N force is zero?
a. The force is exerted at the axis of... Problem 10MCQ: What is the maximum angle to the horizontal you can tilt the candleholder in Figure Q8.10 before it... Problem 11MCQ Problem 12CQ: 12. Is it possible for an object not to be in equilibrium when the net force exerted on it by other... Problem 13CQ: Explain the meaning of torque so that a friend not taking physics can understand. Problem 14CQ Problem 15CQ: What are the two conditions of equilibrium? What happens if one or the other condition is not... Problem 16CQ: Give three examples of situations in which an object is starting to rotate even though the sum of... Problem 17CQ: The force that the body muscles exert on bones that are used to lift various objects is usually five... Problem 18CQ: A ladder leans against a wall. Construct a force diagram showing the direction of all forces exerted... Problem 19CQ: Using a crowbar, a person can remove a nail by exerting little force, whereas pulling directly on... Problem 20CQ: 20. Is it more difficult to do a sit-up with your hands stretched in front of you or with them... Problem 21CQ: Sit on a chair with your feet straight down at the front of the chair. Keeping your back... Problem 22CQ: Can you balance the tip of a wooden ruler vertically on a fingertip? Why is it so difficult? Design... Problem 23CQ: Try to balance a sharp wooden pencil on your fingertip, point down. (Hint: A small pocketknife might... Problem 24CQ: 24. Design a device that you can use to successfully walk on a tightrope.
Problem 25CQ: Explain why it is easier to keep your balance while jumping on two feet than while hopping on one. Problem 26CQ: A carpenters trick to keep nails from bending when they are pounded into a hard material is to grip... Problem 1P: Determine the torques about the axis of rotation P produced by each of the four forces shown in... Problem 2P: 2. Three 200-N forces are exerted on the beam shown in Figure P8.2. (a) Determine the torques about... Problem 3P: 3. * A 2.0-m-long, 15-kg ladder is resting against a house wall, making a 30° angle with the... Problem 4P: Figure P8.4 shows two different situations where three forces of equal magnitude are exerted on a... Problem 5P: Three friends tie three ropes in a knot and pull on the ropes in different directions. Adrienne... Problem 6P Problem 7P: * Kate joins Jim, Luis, and Adrienne in the rope-pulling exercise described in the previous two... Problem 8P: You hang a light in front of your house using an elaborate system to keep the 12- kg light in static... Problem 9P: * Find the values of the forces the ropes exert on the knot if you replace the light in Problem 8.8... Problem 10P Problem 11P: Determine the masses m1 and m2 of the two objects shown in Figure P8.11 if the force exerted by the... Problem 12P: * Lifting an engine You work in a machine shop and need to move a huge 640-kg engine up and to the... Problem 13P: 13. * More lifting You exert a 630-N force on rope 2 in the previous problem (Figure P8.12 ). Write... Problem 14P Problem 15P: 15. * Tightrope walking A tightrope walker wonders if her rope is safe. Her mass is 60 kg and the... Problem 16P: 16. * Lifting patients An apparatus to lift hospital patients sitting at the sides of their beds is... Problem 17P: 17. A father (80 kg), mother (56 kg), daughter (16 kg), and son (24 kg) try to occupy seats on the... Problem 18P Problem 19P: * You place a 3.0-m-long board symmetrically across a 0.5-m-wide chair to seat three physics... Problem 20P Problem 21P Problem 22P Problem 23P: 23. EST Compare the two different designs of nutcracker shown in Figure P8.23 and decide which one... Problem 24P: Ray decides to paint the outside of his uncles house. He uses a 4.0-m-long board supported by... Problem 25P: 25. * A 2.0-m-long uniform beam of mass 8.0 kg supports a 12.0-kg bag of vegetables at one end and a... Problem 26P: * A uniform beam of length / and mass m supports a bag of mass m1 at the left end, another bag of... Problem 27P Problem 28P Problem 29P Problem 30P Problem 31P: 31. * An 80-kg clown sits on a 20-kg bike on a tightrope attached between two trees. The center of... Problem 32P: s center of mass? (Hint: You can think of cutting the hole as adding material of negative mass to... Problem 33P: Leg support A persons broken leg is kept in place by the apparatus shown in Figure P8.33. If the... Problem 34P Problem 35P Problem 36P: * If the force F shown in Figure P8.35 is 840 N and the bottom right edge of the box is slightly off... Problem 37P Problem 38P: 38. * You decide to hang another plant from a 1.5-m-long 2.0-kg horizontal beam that is attached by... Problem 39P Problem 40P: * What mechanical work must you do to lift a log that is 3.0 m long and has a mass of 100 kg from... Problem 41P: 41. * A 70-g meter stick has a 30-g piece of modeling clay attached to the end. Where should you... Problem 42P: * You are trying to tilt a very tall refrigerator (2.0 m high, 1.0 m deep, 1.4m wide, and 100 kg) so... Problem 43P Problem 44P: 44. * You have an Atwood machine (see Figure 4.9 ) with two blocks each of mass m attached to the... Problem 45P: * EST You stand sideways in a moving train. Estimate how far apart you should keep your feet so that... Problem 46GP: 46. EST Your hand holds a liter of milk (mass about 1 kg) while your arm is bent at the elbow in a ... Problem 47GP: EST Body torque You hold a 4.0-kg computer. Estimate the torques exerted on your forearm about the... Problem 48GP Problem 49GP: 49. BIO Using triceps to push a table A man pushes on a table exerting a 20-N downward force with... Problem 50GP Problem 51GP Problem 52GP Problem 53GP: 53.* BIO Dumbbell lift IA woman lifts a 3.6-kg dumbbell in each hand with her arm in a horizontal... Problem 54GP: s shoulder joint exerts on her humerus. Problem 55GP Problem 56GP: * Eiichi has purchased an adjustable hand grip to use for strengthening hands, fingers, and wrists.... Problem 57GP: 57. *BIO While browsing books on neurophysiology, you come across a book published in 1967 by Soviet... Problem 58GP: 58. ** Touch detector You have two force sensors connected to a computer and a meter stick of known... Problem 60GP: * An 80-kg person stands at one end of a 130-kg boat. He then walks to the other end of the boat so... Problem 61GP: 61. EST Two people (50 kg and 75 kg) holding hands stand on Rollerblades 1.0 m apart. (a) Estimate... Problem 62GP Problem 63RPP: BIO Muscles work in pairs Skeletal muscles produce movements by pulling on tendons, which in turn... Problem 64RPP: BIO Muscles work in pairs Skeletal muscles produce movements by pulling on tendons, which in turn... Problem 65RPP: BIO Muscles work in pairs Skeletal muscles produce movements by pulling on tendons, which in turn... Problem 66RPP: BIO Muscles work in pairs Skeletal muscles produce movements by pulling on tendons, which in turn... Problem 67RPP: BIO Improper lifting and the back A careful study of human anatomy allows medical researchers to use... Problem 68RPP: BIO Improper lifting and the back A careful study of human anatomy allows medical researchers to use... Problem 69RPP: BIO Improper lifting and the back A careful study of human anatomy allows medical researchers to use... Problem 70RPP: BIO Improper lifting and the back A careful study of human anatomy allows medical researchers to use... format_list_bulleted