Concept explainers
Native people throughout North and South America used a bola to hunt for birds and animals. A bola can consist of three stones, each with mass m, at the ends of three light cords, each with length ℓ. The other ends of the cords are tied together to form a Y. The hunter holds one stone and swings the other two above his head (Figure P11.41a, page 308). Both these stones move together in a horizontal circle of radius 2ℓ with speed v0. At a moment when the horizontal component of their velocity is directed toward the quarry, the hunter releases the stone in his hand. As the bola flies through the air, the cords quickly take a stable arrangement with constant 120-degree angles between them (Fig. P11.41b). In the vertical direction, the bola is in free fall. Gravitational forces exerted by the Earth make the junction of the cords move with the downward acceleration
Figure P11.41
Trending nowThis is a popular solution!
Chapter 11 Solutions
Bundle: Physics For Scientists And Engineers With Modern Physics, 10th + Webassign Printed Access Card For Serway/jewett's Physics For Scientists And Engineers, 10th, Multi-term
- A child works on a project in art class and uses an outline of her hand on a sheet of construction paper to draw a turkey (Fig. P16.36). The teacher pins the turkey to the bulletin board in the front of the classroom by using a thumbtack. The student notices that if she flicks her finger on the end of the turkey, it oscillates back and forth with a frequency of about 1.65 Hz. If the rotational inertia of the paper turkey is 1.25 105 kgm2 and its mass is 0.005 kg, what is the distance between the thumbtack and the center of mass of the turkey? FIGURE P16.36arrow_forwardA thin rod of length 0.632 m and mass 66.5 g is suspended freely from one end. It is pulled to one side and then allowed to swing like a pendulum, passing through its lowest position with angular speed 1.35 rad/s. Neglecting friction and air resistance, find (a) the rod's kinetic energy at its lowest position and (b) how far above that position the center of mass rises. (a) Number .0080389 Units J (b) Number .12355 Units 3arrow_forwardOne end of a cord is fixed and a small 0.700-kg object is attached to the other end, where it swings in a section of a vertical circle of radius 1.00 m, as shown in the figure below. When θ = 21.0°, the speed of the object is 8.50 m/s. An object is swinging to the right and upward from the end of a cord attached to a horizontal surface. The cord makes an angle θ with the vertical. An arrow labeled vector v points in the direction of motion. (a) At this instant, find the magnitude of the tension in the string. N(b) At this instant, find the tangential and radial components of acceleration. at = m/s2 downward tangent to the circle ac = m/s2 inward (c) At this instant, find the total acceleration. inward and below the cord at °(d) Is your answer changed if the object is swinging down toward its lowest point instead of swinging up? YesNo (e) Explain your answer to part (d).arrow_forward
- Penny is adjusting the position of a stand up piano of mass mp = 150 kg in her living room. The piano is lp = 1.6 m in length. The piano is currently at an angle of θp = 45 degrees to the wall. Penny wants to rotate the piano across the carpeted floor so that it is flat up against the wall. To move the piano, Penny pushes on it at the point furthest from the wall. This piano does not have wheels, so you can assume that the friction between the piano and the rug acts at the center of mass of the piano.Randomized Variables mp = 150 kglp = 1.6 mθp = 45 degrees a) Write an expression for the minimum magnitude of the force Fs in N Penny needs to exert on the piano to get it moving. Assume the corner of the piano on the wall doesn't slide and the static friction between the rug and the piano is μs. Fs,min = b) The coefficient of kinetic friction between the carpet and the piano is μk = 0.27. Once the piano starts moving, calculate the torque τp in N⋅m that Penny needs to apply to keep…arrow_forwardYou have a cylinder. You don't know what its internal structure looks like, but you plan to roll it down a ramp, as in this week's procedure. The ramp is 1 m long, and is elevated at an angle of 15°. The mass of the cylinder is 450 g and its diameter is 2.1 cm.After you release the cylinder, it rolls down the ramp without slipping, gaining speed. How much total energy (in J)does the block have at the bottom of the ramp?arrow_forwardTo test the speed of a bullet, you create a pendulum by attaching a 5.80 kg wooden block to the bottom of a 1.60 m long, 0.800 kg rod. The top of the rod is attached to a frictionless axle and is free to rotate about that point. You fire a 10 g bullet into the block, where it sticks, and the pendulum swings out to an angle of 39.0°. What was the speed of the bullet?arrow_forward
- A person drops a cylindrical steel bar (Y = 1.30 x 10" Pa) from a height of 2.00 m (distance between the floor and the bottom of the vertically oriented bar). The bar, of length L = 0.90 m, radius R = 0.65 cm, and mass m = 1.60 kg, hits the floor and bounces up, maintaining its vertical orientation. Assuming the collision with the floor is elastic, and that no rotation occurs, what is the maximum compression of the bar? AL = mmarrow_forwardA small ball of mass 740.0 g is placed in a tube that is bent into a circular arc of radius R= 67.5 cm.The friction between the ball and the walls of the tube is negligible. The ball has an iron core. A magnet is used to raise the ball until it makes an angle of 5.00 degrees with the vertical, and then released from rest. Where will the ball be 1.20 seconds after being released? Express your answer in terms of the angle,θ, that the ball makes with the vertical.arrow_forward15.124 Arm AB has a constant angular velocity of 16 rad/s counterclockwise. At the instant when 0 = 90°, determine the acceleration of (a) collar D, (b) the midpoint G of bar BD. A 3 in. D 10 in. B G 6 in. Fig. P15.124 and P15.125arrow_forward
- A hollow sphere (I=2/3mr^2) of radius R rotates about a diameter with an angular speed ω. The sphere then collapses (magically) under the action of internal forces to a final radius of R/2 with no change in its mass. What is the final angular speed of the sphere? The answer is 4ω but I'm not sure how to get there.arrow_forwardA bowling ball, whose radius R is 11 cm and whose mass is 7.2 kg. rolls from rest down a plank whose length L is 2.1 m. the plank is inclined at an angle φ of 34 degrees to the horizontal. How fast is the ball moving when it reaches the bottom of the plank? please can you write your answer in handwritten form pleasearrow_forwardGiven a displacement F = 4.0m 1 +9.0m Ĵ +0.0m K, and a momentum p = 10.0N*s 1 + 3.0N*s Ĵ +0.0N*s k Find the angular momentum.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