Description A vertebra is subjected to a shearing force of 495 N. Find the shear deformation, taking the vertebra to be a cylinder 3.00 cm high and 2.00 cm in diameter. The shear modulus for vertebrae is 8.00 × 1010 N/m2.
Description Which one of the following systems would constitute an inertial reference frame? Question 4 options: 1) an orbiting space station 2) a roller coaster traveling around a corkscrew turn at constant speed 3) a rocket undergoing uniform acceleration 4) a rotating merry-go-round 5) a weather balloon descending at constant velocity
Description An artificial satellite circling the Earth completes each orbit in 122 minutes. (a) Find the altitude of the satellite. (b) What is the value of g at the location of this satellite?
Description The densest known element is osmium with a density of ? = 22.4 g/cm3. Suppose two small spheres of osmium with radius 3.00 cm are in contact with each other. Find the gravitational force of attraction between them.In proportion to what power of r does the smallest separation of the sphere centers vary? So the attraction between the spheres of maximum mass at smallest separation increases as r to what power?
Description A person bending forward to lift a load "with his back" (Figure a) rather than "with his knees" can be injured by large forces exerted on the muscles and vertebrae. The spine pivots mainly at the fifth lumbar vertebra, with the principal supporting force provided by the erector spinalis muscle in the back. To see the magnitude of the forces involved, and to understand why back problems are common among humans, consider the model shown in Figure b, of a person bending forward to lift a Wo = 235–N object. The spine and upper body are represented as a uniform horizontal rod of weight Wb = 380 N pivoted at the base of the spine. The erector spinalis muscle, attached at a point two-thirds of the way up the spine, maintains the position of the back. The angle between the spine and this muscle is 12.0°.image.jpg (a) Find the tension in the back muscle. kN (b) Find the compressional force in the spine. (Enter the magnitude.) kN
Description A horizontal 810-N merry-go-round of radius 1.70 m is started from rest by a constant horizontal force of 45 N applied tangentially to the merry-go-round. Find the kinetic energy of the merry-go-round after 4.0 s. (Assume it is a solid cylinder. Also assume the force is applied at the outside edge.)
Description 1. A spiraled tube lies fixed in its horizontal position (i.e., it has been placed upon its side upon a table). When a marble is rolled through it it curves around the tube, explainthe path of the marble after it exits the tube. 2. Rex Things and Doris Locked are out on a date. Rex makes a rapid right-hand turn. Doris begins sliding across the vinyl seat (which Rex had waxed and polished beforehand) and collides with Rex. To break the awkwardness of the situation, Rex and Doris begin discussing the physics of the motion which was just experienced. Rex suggests that objects which move in a circle experience an outward force. Thus, as the turn was made, Doris experienced an outward force which pushed her towards Rex. Doris disagrees, arguing that objects which move in a circle experience an inward force. In this case, according to Doris, Rex traveled in a circle due to the force of his door pushing him inward. Doris did not travel in a circle since their was no force pushing her inward; she merely continued in a straight line until she collided with Rex. Who is correct? Argue one of these two positions. 3. Kara Lott is practicing winter driving in the GBS parking lot. Kara turns the wheel to make a left-hand turn but her car continues in a straight line across the ice. Teacher A and Teacher B had viewed the phenomenon. Teacher A argues that the lack of a frictional force between the tires and the ice results in a balance of forces which keeps the car traveling in a straight line. Teacher B argues that the ice placed an outward force on the tire to balance the turning force and thus keep the car traveling in a straight line. Which teacher is (A or B) is the physics teacher? ______ Explain the fallacy in the other teacher's argument. 4. Anna Litical is practicing a centripetal force demonstration at home. She fills a bucket with water, ties it to a strong rope, and spins it in a circle. Anna spins the bucket when it is half-full of water and when it is quarter-full of water. In which case is more force required to spin the bucket in a circle? Explain using an equation as a "guide to thinking." 5. A Lincoln Continental and a Yugo are making a turn. The Lincoln is four times more massive than the Yugo. If they make the turn at the same speed, then how do the centripetal forces acting upon the two cars compare. Explain. 6. Determine the centripetal force acting upon a 40-kg child who makes 10 revolutions around the Cliffhanger in 29.3 seconds. The radius of the barrel is 2.90 meters.
Description During a race, a runner runs at a speed of 6 m/s. 2 seconds later, she is running at a speed of 10 m/s. What is the runner’s acceleration? Show your work.
