Concept explainers
BIO Heartbeat detector A prisoner tries to escape from a Nashville, Tennessee prison by hiding in the laundry truck. The prisoner is surprised when the truck is stopped at the gate. A guard enters the truck and handcuffs him. “How did you know I was here?” the prisoner asks. “The heartbeat detector,” says the guard.
A heartbeat detector senses the tiny vibrations caused by blood pumped from the heart. With each heartbeat, blood is pumped upward to the aorta, and the body recoils slightly, conserving the momentum of the blood-body system. The body’s vibrations are transferred to the inside of the truck. Vibration sensors on the outside of the truck are linked to a geophone, or signal amplifier, attached to a computer. A wave analyzer program in the computer compares vibration signals from the truck to wavelets produced by heartbeat vibrations. The wave analyzer distinguishes a person’s heartbeat from other vibrations in the truck or in the surrounding environment, allowing guards to detect the presence of a human in the truck.
What does the heartbeat detector sense?
a. Electric signals caused by electric dipole charges produced on the heart
b. Body vibrations caused by blood pumped from the heart
c. Sound caused by breathing
d. Slight uncontrollable reflexive motions of an enclosed person
e. All of the above
Want to see the full answer?
Check out a sample textbook solutionChapter 6 Solutions
College Physics
Additional Science Textbook Solutions
Life in the Universe (4th Edition)
Cosmic Perspective Fundamentals
Modern Physics
University Physics Volume 2
Physics (5th Edition)
The Cosmic Perspective Fundamentals (2nd Edition)
- A system consists of three particles, each of mass 5.00 g, located at the corners of an equilateral triangle with sides of 30.0 cm. (a) Calculate the gravitational potential energy of the system. (b) Assume the particles are released simultaneously. Describe the subsequent motion of each. Will any collisions take place? Explain.arrow_forwardA suspicious physics student watches a stunt performed at an ice show. In the stunt, a performer shoots an arrow into a bale of hay (Fig. P11.24). Another performer rides on the bale of hay like a cowboy. After the arrow enters the bale, the balearrow system slides roughly 5 m along the ice. Estimate the initial speed of the arrow. Is there a trick to this stunt? FIGURE P11.24arrow_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
- When a person feels that he is about to fall, he will often put out his hand to try to break the fall. Explain why this natural reaction usually leads to bruises or minor broken bones such as in the wrists instead of major broken bones such as the skull.arrow_forwardQUESTION 2 Problem A new type of force was discovered by physicists with the following expression: a Fnew + Be* + 3x4 %3D where alpha & beta are constants, and x is the position. The expression above was obtained from the interaction of a massless Higgs Boson (a type of particle) and a black hole. Quantum physicists then decides to design and build a machine that is able to move the Higgs Boson from x, to x1. How much work should the machine do to achieve this feat? (For simplicity, consider that no energy is lost in the process) Solution To determine the work done we apply the following W = dx Evaluating the above, we get W = for the limits from xj to Xf substituting x1 and x, as the limits, the work done is expressed as | + Bi X1 W = x15 - x25 )arrow_forwardQUESTION 2 Problem A new type of force was discovered by physicists with the following expression: a Fnew=x + Be* + 3x4 where alpha & beta are constants, and x is the position. The expression above was obtained from the interaction of a massless Higgs Boson (a type of particle) and a black hole. Quantum physicists then decides to design and build a machine that is able to move the Higgs Boson from x, to x1. How much work should the machine do to achieve this feat? (For simplicity, consider that no energy is lost in the process) Solution To determine the work done we apply the following W = dx Evaluating the above, we get W = for the limits from x; to Xf substituting x1 and x, as the limits, the work done is expressed as W = Bi X1 ( x15 - x2)arrow_forward
- You are standing on a saucer-shaped sled at rest in the middle of a frictionless ice rink. Your lab partner throws you a heavy Frisbee You take different actions in successive experimental trials. Rank the following situations according to your final speed from largest to smallest. If your final speed is the same in two cases, give them equal rank. (a) You catch the Frisbee and hold onto it. (b) You catch the Frisbee and throw it back to your partner. (c) You bobble the catch, just touching the Frisbee so that it continues in its original direction more slowly. (d) You catch the Frisbee and throw it so that it moves vertically upward above your head. (e) You catch the Frisbee and set it down so that it remains at rest on the ice.arrow_forwardTwo children, with masses m1 = 35.0 kg and m2 = 43.0 kg, are swinging on a tire swing attached to a tree overhanging a pond. The mass of the tire is negligible. At the lowest point of the swinging motion, the tension in each of the three vertical 4.00-m-long chains supporting the swing is 275 N. a. What is the speed of the children at the lowest point of the swinging motion? b. What is the force exerted on each child by the tire at the lowest point of the swinging motion?arrow_forwardA 44.0-kg child finds himself trapped on the surface of a frozen lake, 10.0 m from the shore. The child slips with each step on the frictionless ice and remains the same distance from the shoreline. Egged on by his parents, he throws a 0.750-kg ball he is carrying toward the center of the lake with a horizontal speed of 1.50 m/s, in the direction opposite that of the shoreline. a. Does the act of throwing the ball cause the child to move? If so, what are the speed and the direction of his motion with respect to the Earth? b. What are the forces acting on the child when he throws the ball?arrow_forward
- Consider the Earth and the Moon as a two-particle system. a. Find an expression for the gravitational field g of this two-particle system as a function of the distance r from the center of the Earth. (Do not worry about points inside either the Earth or the Moon.) b. Plot the scalar component of g as a function of distance from the center of the Earth.arrow_forwardYou have just planted a sturdy 2-m-tall palm tree in your front lawn for your mother's birthday. Your brother kicks a 500 g ball, which hits the top of the tree at a speed of 5 m/s and stays in contact with it for 10 ms. The ball falls to the ground near the base of the tree and the recoil of the tree is minimal. (a) What is the force on the tree? (b) The length of the sturdy section of the root is only 20 cm. Furthermore, the soil around the roots is loose and we can assume that an effective force is applied at the tip of the 20 cm length. What is the effective force exerted by the end of the tip of the root to keep the tree from toppling? Assume the tree will be uprooted rather than bend. (c) What could you have done to ensure that the tree does not uproot easily?arrow_forward19. * Equation Jeopardy 1 The equations be- low describe one or more physical process- es. Solve the equations for the unknowns and write a problem statement for which the equations are a satisfactory solution. - - (0.001 kg)(9.8 N/kg) + T sin 88° = 0 ( − 5.0 × 10¯³C)Ex + Tcos 88° = 0 -arrow_forward
- Physics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax CollegePhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning