Concept explainers
Review. Why is the following situation impossible? An athlete tests her hand strength by having an assistant hang weights from her belt as she hangs onto a horizontal bar with her hands. When the weights hanging on her belt have increased to 80% of her body weight, her hands can no longer support her and she drops to the floor. Frustrated at not meeting her hand-strength goal, she decides to swing on a trapeze. The trapeze consists of a bar suspended by two parallel ropes, each of length ℓ, allowing performers to swing in a vertical circular are (Fig. P8.38). The athlete holds the bar and steps off an elevated platform, starting from rest with the ropes at an angle θi = 60.0° with respect to the vertical. As she swings several times back and forth in a circular are, she forgets her frustration related to the hand-strength test. Assume the size of the performer’s body is small compared to the length ℓ and air resistance is negligible.
Figure P8.38
Want to see the full answer?
Check out a sample textbook solutionChapter 8 Solutions
Physics for Scientists and Engineers, Technology Update (No access codes included)
- Could anyone help me with my physics homework?arrow_forwardHanging Mass: A block of mass 14.1 kg is connected to a light cord of length 351.3 cm and a spring with an equilibrium length of 33.4 cm. The block hangs motionless as shown in the figure. The spring has a spring constant of 1799 N/ m. As the block hangs in equilibrium, the spring is horizontal and the cord makes an angle of 24 ° with respect to vertical. T k M (a) What is the tension in the cord? (b) How far is the spring stretched from its equilibrium length?arrow_forwardA movie stunt performer is filming a scene where he swings across a river on a vine. The safety crew must use a vine with enough strength so that it doesn't break while swinging. The stunt performer's mass is 88.0 kg, the vine is 12.0 m long, and the speed of the stunt performer at the bottom of the swing has been determined to be 7.80 m/s. What is the minimum tension force (in N) the vine must be able to support without breaking? ____Narrow_forward
- A movie stunt performer is filming a scene where he swings across a river on a vine. The safety crew must use a vine with enough strength so that it doesn't break while swinging. The stunt performer's mass is 90.0 kg, the vine is 11.0 m long, and the speed of the stunt performer at the bottom of the swing has been determined to be 7.40 m/s. What is the minimum tension force (in N) the vine must be able to support without breaking? Aa N Need Help? Read Itarrow_forwardProblem. An object with mass m₁ = 7 kg moves on a level, frictionless table in a physics lab. It is then connected to a hanging weight with m₂ = 12 kg by a string passing over a small frictionless pulley. The string is light and flexible, and it doesn't stretch. What would be the resulting value of the Tension in the given system? O 74.4 N 43.3 N 56.9 N 23.4 Narrow_forwardAnswer either this question or the next. L M Ax 3. A pendulum of length L = 1.0 meter and bob with mass m = 1.0 kg is released from rest at an angle 30° from the vertical. When the pendulum reaches the vertical position, the bob strikes a mass M = 3.0 kg that is resting on a frictionless table of height h = 0.85 m. You may assume the string is massless, and drag is negligible. a. Calculate the speed of the bob just before it strikes the box (i.e., when the pendulum string hangs straight down). b. Calculate the speeds of the bob and the box just after they collide elastically. c. Determine the impulse that acts on the box during the collision. d. Determine how far from the bottom edge of the table, Ax, the box lands.arrow_forward
- You are part of the stage crew for a theatrical company and are designing an apparatus to support an actor of mass 65.0 kg who is to “fly” down to the stage during the performance of a play. You attach the actor’s harness to a 130-kg sandbag by means of a lightweight steel cable running smoothly over two frictionless pulleys as in 8.5a. You need 3.00 m of cable between the harness and the nearest pulley so that the pulley can be hidden behind a curtain. For the apparatus to work successfully, the sandbag must never lift above the floor as the actor swings from above the stage to the floor. Let us call the initial angle that the actor’s cable makes with the vertical θ. What is the maximum value θ can have before the sandbag lifts off the floor?arrow_forwardTwo objects are connected by a light string passing over a light, frictionless pulley as shown in the figure below. The object of mass m1 = 5.20 kg is released from rest at a height h = 4.40 m above the table. Two objects are connected by a taught string passing over a pulley. An object labeled m2 rests on a table, and an object labeled m1 dangles a distance h above the table. (a) Using the isolated system model, determine the speed of the object of mass m2 = 3.00 kg just as the 5.20–kg object hits the table.m/s(b) Find the maximum height above the table to which the 3.00–kg object rises.arrow_forwardTo give a pet hamster exercise, some people put the hamster in a ventilated ball andallow it roam around the house(Fig. P13.66). When a hamsteris in such a ball, it can cross atypical room in a few minutes.Estimate the total kinetic energyin the ball-hamster system. FIGURE P13.66 Problems 66 and 67arrow_forward
- Review. Why is the following situation impossible? An athlete tests her hand strength by having an assistant hang weights from her belt as she hangs onto a horizontal bar with her hands. When the weights hanging on her belt have increased to 80% of her body weight, her hands can no longer support her and she drops to the floor. Frustrated at not meeting her hand-strength goal, she decides to swing on a trapeze. The trapeze consists of a bar suspended by two parallel ropes, each of length , allowing performers to swing in a vertical circular are (Fig. P8.38). The athlete holds the bar and steps off an elevated platform, starting from rest with the ropes at an angle i = 60.0 with respect to the vertical. As she swings several times back and forth in a circular are, she forgets her frustration related to the hand-strength test. Assume the size of the performers body is small compared to the length and air resistance is negligible. Figure P8.38arrow_forwardA small ball is tied to a string and hung as shown in Figure P8.34. It is released from rest at position 1, and, during the swing, the string meets a fixed peg as shown. Explain why position 2 at which the ball comes momentarily to rest must be at the same height as position 1.arrow_forwardAn airplane of mass 3.60 × 105 kg experienced a problem with all its tires when it was about to touch down at a runway of an airport. The tires were deadlocked and not able to roll. The airplane began to skid once it touched down and left behind a 728 m long skid mark on the runway before it came to a stop. Even though everyone on the airplane was safe, the pilot was accused of failing to land the airplane within the allowable speed limit of 80.0 m/s and his pilot license was suspended. Given that the coefficient of kinetic friction between the tires and runway was 0.496. (i) Determine the work done by friction on the tires.(ii) Use the Work-Energy Theorem to evaluate if the suspension of the pilot’s license should be revoked. #This is an exercise question, please help. Thank You.arrow_forward
- Physics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning