The ultracentrifuge is an important tool for separating and analyzing proteins in biological research. Because of the enormous centripetal accelerations that can be achieved, the apparatus (see Figure 6.18) must be carefully balanced so that each sample is matched by another on the opposite side of the rotor shaft. Failure to do so is a costly mistake, as seen in Figure P6.64. Any difference in mass of the opposing samples will cause a net force in the horizontal plane on the shaft of the rotor. Suppose that a scientist makes a slight error in sample preparation, and one sample has a mass 10 mg greater than the opposing sample. If the samples are 10 cm from the axis of the rotor and the ultracentrifuge spins at 70,000 rpm, what is the magnitude of the net force on the rotor due to the unbalanced samples?
Figure P6.64
Want to see the full answer?
Check out a sample textbook solutionChapter 6 Solutions
College Physics: A Strategic Approach (3rd Edition)
Additional Science Textbook Solutions
Lecture- Tutorials for Introductory Astronomy
Physics for Scientists and Engineers with Modern Physics
Physics: Principles with Applications
Essential University Physics (3rd Edition)
Introduction to Electrodynamics
- 8:37 ull LTE 1 Safari 9. A student is riding on a carousel at a speed of 4.0 m/s. If the Carousel has a radius of 5.0 m and the centripetal force is 240 N, what is the student's mass? 10. A 25 kg girl sitting on a carousel is moving at a speed of 4.0 m/s. If the girl is 5.0 m from the axis of the carousel, what is the centripetal force that maintains her circular motion? 11. A NASCAR driver weighing 75 kg enters a corner with a radius of 155 m with a speed of 125 m/s. What is the centripetal force that maintains his circular motion? 12. A girl sits on a tire swing that is attached with a rone that is 2.10 m in length. Her dad pushes her with a of 2.5 m/s. If the centripetal force is 88.0 N, what girl's mass?arrow_forwardYou tie one end of 0.3-m-long spring to a 0.5 kg mass. Holding the other end of the spring in your hand, you whirl the mass in a vertical circle at a speed of 4 m/s. If the spring elongates 1 cm at the lowest point in the circular motion, what is the spring constant?arrow_forwardA racetrack has the shape of an inverted cone, as the drawing shows. On this surface the cars race in circles that are parallel to the ground. For a speed of 47.5 m/s, at what value of the distance d should a driver locate his car if he wishes to stay on a circular path without depending on friction?arrow_forward
- Suppose you are a roller coaster ride designer and you begin a new design with safety in mind. Safety regulations state that the riders' centripetal acceleration should be no more than n = 1.65g at the top of the hump and no more than N = 5.50g at the bottom of the hoop. Previous sections of the ride give the train a speed of 11.3 m/s at the top of the incline, which is h = 37.5 m above the ground (see figure). Ignoring the effects of friction and air resistance: (a) What is the minimum radius Rhump you can use for the semi-circular hump? (b) What is the minimum radius Rloop you can use for the vertical loop? h R hump R looparrow_forwardYou are designing the section of a roller coaster ride shown in the figure. Previous sections of the ride give the train a speed of 10.7 m/s at the top of the incline, which is h=37.5 m above the ground. As any good engineer would, you begin your design with safety in mind. Your local government's safety regulations state that the riders' centripetal acceleration should be no more than n=1.73 g at the top of the hump and no more than N=5.45 gat the bottom of the loop. For this initial phase of your design, you decide to ignore the effects of friction and air resistance. (Figure not to scale)What is the minimum radius Rhump you can use for the semi-circular hump?What is the minimum radius Rloop you can use for the vertical loop?arrow_forwardYou are designing the section of a roller coaster ride shown in the figure. Previous sections of the ride give the train a speed of 15.5 m/s at the top of the incline, which is h = 36.7 m above the ground. As any good engineer would, you begin your design with safety in mind. Your local government's safety regulations state that the riders' centripetal acceleration should be no more than n = 1.77 g at the top of the hump and no more than N = 5.37 g at the bottom of the loop. For this initial phase of your design, you decide to ignore the effects of friction and air resistance. (Figure not to scale) What is the minimum radius Rhump you can use for the semi-circular hump? Rhump = What is the minimum radius Roop you can use for the vertical loop? Roop= R₁000 m marrow_forward
- 7:31 l LTE 4 1 Safari A Ferris wheel is traveling at a constant speed in a counter-clockwise direction as shown in the diagram. The people at location P are accelerating which direction? D A) A В) В C) C D) D A 35 kg girl sitting on a Ferris wheel is moving at a speed of 8.0 m/s. If the girl is 15.0 m from the axis of the carousel, what is the centripetal force that maintains her circular motion? A 25 kg girl sitting on a carousel is moving at a speed of 4.0 m/s. If the centripetal force acting on the girl is 45 N how far from the axis of the carousel is she sitting?arrow_forwardA 70 kg person is sitting on a bathroom scale while riding on a Ferris Wheel. The Ferris Wheel has a radius of 9 m. The scale reads 900 N when the person is at the bottom of the motion. Find the person's speed.arrow_forwardA 0.5 kg object moves in a horizontal circular track with a radius of 2.5 m. An external force of 3.0 N, acting always tangent to the track, causes the object to speed up as it goes around. If it starts from rest, its speed at the end of one revolution is:arrow_forward
- A certain string just breaks when it is under 23 N of tension. A boy uses this string to rotate a 660 g stone in a horizontal circle of radius 2.0 m. The boy continuously increases the speed of the stone. At approximately what speed will the string break? (Hint: you may assume that the string is about to break and it hasn't broken yet). O 8.35 m/s O 0.264 m/s O 69.7 m/s O0.0143 m/sarrow_forwardA wind turbine has 12,000 kg blades that are 39 m long. The blades spin at 23 rpm .If we model a blade as a point mass at the midpoint of the blade, what is the inward force necessary to provide each blade's centripetal acceleration?Express your answer to two significant figures and include the appropriate units.arrow_forwardA 0.250 kg ball swings in a vertical circle on the end of a string that is 1.20 m long. The tension in the string is 15.0 N when it is falling toward the lowest point on the circle and the angle between the string and the vertical is 40.0°. What is the speed of the ball at this moment?arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher: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
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning