![University Physics with Modern Physics (14th Edition)](https://www.bartleby.com/isbn_cover_images/9780321973610/9780321973610_largeCoverImage.gif)
Concept explainers
BIO THE DNA SPRING. A DNA molecule, with its double-helix structure, can in some situations behave like a spring. Measuring the force required to stretch single DNA molecules under various conditions can provide information about the biophysical properties of DNA. A technique for measuring the stretching force makes use of a very small cantilever, which consists of a beam that is supported at one end and is free to move at the other end. like a tiny diving board. The cantilever is constructed so that it obeys Hooke’s law—that is the displacement of its free end is proportional to the force applied to it. Because different cantilevers have different force constants, the cantilever's response must first be calibrated by applying a known force and determining the resulting deflection of the cantilever. Then one end of a DNA molecule is attached to the free end of the cantilever, and the other end of the DNA molecule is attached to a small stage that can be moved away from the cantilever, stretching the DNA. The stretched DNA pulls on the cantilever, deflecting the end of the cantilever very slightly. The measured deflection is then used to determine the force on the DNA molecule.
7.84 The stage moves at a constant speed while stretching the DNA. Which of the graphs in Fig. P7.84 best represents the power supplied to the stage versus time?
![Check Mark](/static/check-mark.png)
Trending nowThis is a popular solution!
![Blurred answer](/static/blurred-answer.jpg)
Chapter 7 Solutions
University Physics with Modern Physics (14th Edition)
Additional Science Textbook Solutions
Life in the Universe (4th Edition)
Conceptual Physics (12th Edition)
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)
College Physics
Glencoe Physical Science 2012 Student Edition (Glencoe Science) (McGraw-Hill Education)
- A small block of mass m = 200 g is released from rest at point along the horizontal diameter on the inside of a frictionless, hemispherical bowl of radius R = 30.0 cm (Fig. P7.45). Calculate (a) the gravitational potential energy of the block-Earth system when the block is at point relative to point . (b) the kinetic energy of the block at point , (c) its speed at point , and (d) its kinetic energy and the potential energy when the block is at point . Figure P7.45 Problems 45 and 46.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_forwardA small 0.65-kg box is launched from rest by a horizontal spring as shown in Figure P9.50. The block slides on a track down a hill and comes to rest at a distance d from the base of the hill. Kinetic friction between the box and the track is negligible on the hill, but the coefficient of kinetic friction between the box and the horizontal parts of track is 0.35. The spring has a spring constant of 34.5 N/m, and is compressed 30.0 cm with the box attached. The block remains on the track at all times. a. What would you include in the system? Explain your choice. b. Calculate d.arrow_forward
- The Flybar high-tech pogo stick is advertised as being capable of launching jumpers up to 6 ft. The ad says that the minimum weight of a jumper is 120 lb and the maximum weight is 250 lb. It also says that the pogo stick uses a patented system of elastometric rubber springs that provides up to 1200 lbs of thrust, something common helical spring sticks simply cannot achieve (rubber has 10 times the energy storing capability of steel). a. Use Figure P8.32 to estimate the maximum compression of the pogo sticks spring. Include the uncertainty in your estimate. b. What is the effective spring constant of the elastometric rubber springs? Comment on the claim that rubber has 10 times the energy-storing capability of steel. c. Check the ads claim that the maximum height a jumper can achieve is 6 ft.arrow_forwardReview. The mass of a car is 1 500 kg. The shape of the cars body is such that its aerodynamic drag coefficient is D = 0.330 and its frontal area is 2.50 m2. Assuming the drag force is proportional to 2 and ignoring other sources of friction, calculate the power required to maintain a speed of 100 km/h as the car climbs a long hill sloping at 3.20.arrow_forwardTruck suspensions often have "helper springs" that engage at high loads. One such arrangement is a leaf spring with a helper coil spring mounted on the axle, as shown in the figure below. When the main leaf spring is compressed by distance yo, the helper spring engages and then helps to support any additional load. Suppose the leaf spring constant is 4.90 x 105 N/m, the helper spring constant is 3.60 x 105 N/m, and yo = 0.500 m. Truck body Axle (a) What is the compression of the leaf spring for a load of 4.70 x 105 N? 0.87 Your response differs from the correct answer by more than 10%. Double check your calculations. m (b) How much work is done in compressing the springs? 0.855 Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully. Jarrow_forward
- Pete Zaria works on weekends at Barnaby's Pizza Parlor. His primary responsibility is to fill drink orders for customers. He fills a pitcher full of Cola, places it on the counter top and gives the 2.6-kg pitcher a 8.8 N forward push over a distance of 48 cm to send it to a customer at the end of the counter. The coefficient of friction between the pitcher and the counter top is 0.28. a. Determine the work done by Pete on the pitcher during the 48 cm push.b. Determine the work done by friction upon the pitcher .c. Determine the total work done upon the pitcher .d. Determine the kinetic energy of the pitcher when Pete is done pushing it.e. Determine the speed of the pitcher when Pete is done pushing it.arrow_forwardEd, Edd and Eddy love to play on a seesaw. It consists of a 1-kg board with a length of 8 meters. One day, the other end broke down. They had to cut it by a meter and maintain the pin support in its original position. Then, they tried the seesaw altogether. Ed (m = 55kg) sat on one side about 3m from the pin while Edd (m = 40kg) and Eddy (m = 40kg) on the other side. If Edd was about 3m as well from the pin, calculate the following: The magnitude of the reaction force (N) exerted by the pin support on the board. Assume Eddy is in between Ed and Edd. (mass of board = 125g/m)arrow_forwardIn a basketball game, lebron made a dunk. At the time he was hanging on to the rim, the rim was displaced 15cm and he was 1.5m above the floor. Let us say that lebron has a point mass of 110 kilograms, and the force constant of the rim is 7 kN/m what is his total potential energy while he is hanging on the rim? A. 79 J B. 80 J C. 2405 J D. 1617 J E. 1696 Jarrow_forward
- A 5.2-kg bowling ball is attached to a weightless rod with dimensions shown below. The other end is attached to a rusty hinge so that it can swing like a pendulum. The ball is released when the rod is horizontal and the ball swings down and then up to a certain angle on the other side. During the swing, the rusty hinge steals 80% of the ball's initial potential energy. Find the maximum angle 0 of the rod from the vertical. 2.30 m-arrow_forward63. A 10.0-kg block is released from rest at point in Fig- Mure P8.63. The track is frictionless except for the por- tion between points and ©, which has a length of 6.00 m. The block travels down the track, hits a spring of force constant 2 250 N/m, and compresses the spring 0.300 m from its equilibrium position before coming to rest momentarily. Determine the coefficient of kinetic friction between the block and the rough surface between points and ©. 3.00 m 6.00 m Figure P8.63arrow_forwardTruck suspensions often have "helper springs" that engage at high loads. One such arrangement is a leaf spring with a helper coil spring mounted on the axle, as shown in the figure below. When the main leaf spring is compressed by distance yo, the helper spring engages and then helps to support any additional load. Suppose the leaf spring constant is 4.80 x 10° N/m, the helper spring constant is 3.80 x 10° N/m, and Y. = 0.500 m. Truck body -"Helper" spring Main leaf spring Axle (a) What is the compression of the leaf spring for a load of 5.10 x 10° N? 0 81 (b) How much work is done in compressing the springs? 1 34 Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully. J Need Help? Read Itarrow_forward
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics 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 Learning
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning
![Text book image](https://www.bartleby.com/isbn_cover_images/9781133104261/9781133104261_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781337553292/9781337553292_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781337553278/9781337553278_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781133939146/9781133939146_smallCoverImage.gif)