
Concept explainers
BIO Compressing the Ground A running track at Harvard University uses a surface with a force constant of 2.5 × 105N/m. This surface is compressed slightly every time a runner’s foot lands on it. The force exerted by the foot, according to the Saucony shoe company, has a magnitude of 2700 N for a typical runner. Treating the tracks surface as an ideal spring, find (a) the amount of compression caused by a foot hitting the track and (b) the energy stored briefly in the track every time a foot lands.

Want to see the full answer?
Check out a sample textbook solution
Chapter 8 Solutions
Physics (5th Edition)
Additional Science Textbook Solutions
Organic Chemistry (8th Edition)
Biology: Life on Earth with Physiology (11th Edition)
Physics for Scientists and Engineers: A Strategic Approach, Vol. 1 (Chs 1-21) (4th Edition)
Applications and Investigations in Earth Science (9th Edition)
Chemistry: An Introduction to General, Organic, and Biological Chemistry (13th Edition)
Introductory Chemistry (6th Edition)
- No chatgpt pls will upvote Already got wrong chatgpt answerarrow_forwardWhat is the practical benefit (in terms of time savings and efficiency) of defining the potential energy? Be clear about what is required in terms of calculation if we do not use the concept of potential energy.arrow_forwardWhat is the critical angle fir the light travelling from the crown glass(n=1.52) into the air(n=1.00)?arrow_forward
- No chatgpt pls will upvotearrow_forwardYou are working with a team that is designing a new roller coaster-type amusement park ride for a major theme park. You are present for the testing of the ride, in which an empty 150 kg car is sent along the entire ride. Near the end of the ride, the car is at near rest at the top of a 100 m tall track. It then enters a final section, rolling down an undulating hill to ground level. The total length of track for this final section from the top to the ground is 250 m. For the first 230 m, a constant friction force of 370 N acts from computer-controlled brakes. For the last 20 m, which is horizontal at ground level, the computer increases the friction force to a value required for the speed to be reduced to zero just as the car arrives at the point on the track at which the passengers exit. (a) Determine the required constant friction force (in N) for the last 20 m for the empty test car. Write AK + AU + AE int = W+Q + TMW + TMT + TET + TER for the car-track-Earth system and solve for…arrow_forward= 12 kg, and m3 Three objects with masses m₁ = 3.8 kg, m₂ find the speed of m3 after it moves down 4.0 m. m/s 19 kg, respectively, are attached by strings over frictionless pulleys as indicated in the figure below. The horizontal surface exerts a force of friction of 30 N on m2. If the system is released from rest, use energy concepts to m m2 m3 iarrow_forward
- Three objects with masses m₁ = 3.8 kg, m₂ = 12 kg, and m 19 kg, respectively, are attached by strings over frictionless pulleys as indicated in the figure below. The horizontal surface exerts a force of friction of 30 N on m2. If the system is released from rest, use energy concepts to find the speed of m¸ after it moves down 4.0 m. m/s m m2 mgarrow_forwardIn order for Jane to return to base camp, she needs to swing across a river of width D that is filled with alligators. She must swing into a wind exerting constant horizontal force F, F = 110 N, L = 40.0 m, 0 = 50.0°, and her mass to be 50.0 kg. Wind →F Tarzan! Jane (a) with what minimum speed (in m/s) must Jane begin her swing to just make it to the other side? (If Jane can make it across with zero initial velocity, enter 0.) m/s on a vine having length L and initially making an angle with the vertical (see below figure). Take D = 48.0 m, (b) Shortly after Jane's arrival, Tarzan and Jane decide to swing back across the river (simultaneously). With what minimum speed (in m/s) must they begin their swing? Assume that Tarzan has a mass of 80.0 kg. m/sarrow_forwardR=2.00 12V 2.00 4.00 4.002 What is the current in one of the 4.0 Q resistors? An isolated point charge q is located at point X. Two other points Y and Z are such that YZ2 XY. Y X What is (electric field at Y)/(electric field at Z)?arrow_forward
- Two objects (m₁ = 4.75 kg and m₂ 2.80 kg) are connected by a light string passing over a light, frictionless pulley as in the figure below. The 4.75-kg object is released from rest at a point h = 4.00 m above the table mg m (a) Determine the speed of each object when the two pass each other. m/s (b) Determine the speed of each object at the moment the 4.75-kg object hits the table. m/s (c) How much higher does the 2.80-kg object travel after the 4.75-kg object hits the table? marrow_forwardA cell of negligible internal resistance is connected to three identical resistors. The current in the cell is 3.0 A. The resistors are now arranged in series. What is the new current in the cell?arrow_forwardA negatively charged sphere is falling through a magnetic field. north pole of magnet direction of motion south pole of magnet What is the direction of the magnetic force acting on the sphere?arrow_forward
- Physics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author: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
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning





