Concept explainers
Integrated Concepts
The 70.0-kg swimmer in Figure 7.44 starts a race with an initial velocity of 1.25 m/s and exerts an average force of 80.0 N backward with his arms during each 1.80 m long stroke. (a) What is his initial acceleration if water resistance is 45.0 N? (b) What is the subsequent average resistance force from the water during the 5.00 s it takes him to reach his top velocity of 2.50 m/s? (c) Discuss whether water resistance seems to increase linearly with velocity.
Trending nowThis is a popular solution!
Chapter 7 Solutions
College Physics
Additional Science Textbook Solutions
Lecture- Tutorials for Introductory Astronomy
University Physics Volume 2
Physics: Principles with Applications
College Physics: A Strategic Approach (4th Edition)
University Physics with Modern Physics (14th Edition)
College Physics (10th Edition)
- Check Your Understanding You probably recall that, neglecting air resistance, if you throw a projectile straight up, the time ii takes to reach its maximum height equals the time it takes to fall from the maximum height back to the starting height. Suppose you cannot neglect air resistance, as in Example 8.8. Is the time the projectile takes to go up (a) greater than, (b) less than, or (c) equal to the time It takes to come back down? Explain.arrow_forwardThere is a 5K event coming up in your town. While talking to your grandmother, who uses an electric scooter for mobility, she says that she would like to accompany you on her scooter while you walk the 5.00-km distance. The manual that came with her scooter claims that the fully charged battery is capable of providing 120 Wh of energy before being depleted. In preparation for the race, you go for a test drive: beginning with a fully charged battery, your grandmother rides beside you as you walk 5.00 km on flat ground. At the end of the walk, the battery usage indicator shows that 40.0% of the original energy in the battery remains. You also know that the combined weight of the scooter and your grandmother is 890 N. A few days later, filled with confidence that the battery has sufficient energy, you and your grandmother drive to the 5K event. Unbeknownst to you, the 5K route is not on flat ground, but is all uphill, ending at a point higher than the starting line. A race official tells you that the total amount of vertical displacement on the route is 150 m. Should your grandmother accompany you on the walk, or will she be stranded when her battery runs out of energy? Assume that the only difference between your test drive and the actual event is the vertical displacement.arrow_forwardWhich of the following is a unit of work? (4.1) (a) W (b) J s (c) N/s (d) N marrow_forward
- Integrated Concepts A 75.0-kg cross-country skier is climbing a 3.0° slope at a constant speed of 2.00 m/s and encounters air resistance of 25.0 N. Find his power output for work done against the gravitational force and air resistance. (b) What average force does he exert backward on the snow to accomplish this? (c) If he continues to exert this force and to experience the same air resistance when he reaches a level area, how long will it take him to reach a velocity of 10.0 m/s?arrow_forwardSuppose you drop a metal ball from the top of the building that is 250 meters high. The ball has a MASS of 2 kg and the resistance force is given by 4v How long will take the ball to reach the ground? What will be its velocity at that time?arrow_forwardQUESTION 13 A stone of mass 3 kg is dropped into a water tank. The stone has negligible speed when entering the water surface and takes 3 seconds to sink to the bottom. While sinking, the resistance of the water is 9N. The acceleration of the stone and the height of water column are respectively : O 1.6.81 ms-2, 30.64 m O 2.9.81 ms-2, 44.1 m O 3. (-) 9.81 ms-2, 44.1 m O 4.12.81 ms 2, 57.6 marrow_forward
- The 78.5-kg swimmer in the figure starts a race with an initial velocity of 1.4 m/s and exerts an average force of 78.5 N backward with his arms during each 1.80 m long stroke. What is the subsequent average resistance force, in newtons, from the water during 5.25s it takes him to reach his top velocity of 2.55 m/s?arrow_forwardHow do you overcome resistance when working through a difficult problem?arrow_forwardA body of mass 4 kg is projected upward with an initial velocity of 30 m/s. The air resistance is 0.01v N where v is in m/s. How long (in seconds) does the body reaches the maximum height? (Use four decimal places) Group of answer choices 2.9468 s 1.9468 s 4.7581 s 3.7218 sarrow_forward
- Please solve this physics question with all parts answered and all work shown with the answers by the indicated question number.arrow_forwardOO O O Question 11 Q Zoom Q Review / v Finis ABC O Question 11 Luisa used a claw hammer to remove nails from a piece of wood she wants to paint. What is the effort distance for a claw hammer if the resistance distance is 6.0 cm and the mechanical advantage is 6.0? A 24 27 30 36 O Time Remaining: 1 hour. 3 minutes OzueiIluminate EducationTM, Inc. 000 12:44 hp C esc 23 2$ 8. 9. 6 7arrow_forwardThe figure shows two crates, each of mass m = 24 kg, that are connected by a very light wire. The coefficient of kinetic friction between the crate on the inclined surface and the surface itself is 0.31. Find the speed of the crates after they have moved 1.6 m starting from rest.arrow_forward
- College PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax CollegePrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningUniversity Physics Volume 1PhysicsISBN:9781938168277Author:William Moebs, Samuel J. Ling, Jeff SannyPublisher:OpenStax - Rice UniversityPhysics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning