1. [-/2 Points] DETAILS OSCOLPHYS2016 9.2.P.001. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER (a) When opening a door, you push on it perpendicularly with a force of 47.0 N at a distance of 0.750 m from the hinges. What torque (in N.m) are you exerting relative to the hinges? (Enter the magnitude.) N.m (b) Does it matter if you push at the same height as the hinges? O Yes O No Additional Materials Reading 2. [-/1 Points] DETAILS OSCOLPHYS2016 9.2.P.003. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Two children push on opposite sides of a door during play. Both push horizontally and perpendicular to the door. One child pushes with a force of 165 N at a distance of 0.600 m from the hinges, and the second pushes at a distance of 0.450 m. What force (in N) must the second exert to keep the door from moving? Assume friction is negligible. N X Additional Materials Reading3. [-/1 Points] DETAILS OSCOLPHYS2016 9.2.P.004. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER The two children shown in the figure below are balanced on a seesaw of negligible mass. The first child has a mass of 25.3 kg and sits 1.54 m from the pivot. The second child has a mass of 41.7 kg and sits 0.934 m from the pivot. Use the second condition for equilibrium (net 7 = 0) to calculate F, the supporting force (in N) exerted by the pivot. (Enter the magnitude.) m2 12 W2 N Additional Materials Reading4. [-12 Points] DETAILS OSCOLPHYSZO16 9.5.P.024. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Suppose you use an ideal pulley of the type shown in image (a) in the gure below to support a car engine of mass 120 kg. (a) [b] (a) What would be the tension in newtons in the rope? :IN (b) What force in newtons must the ceiling supply, assuming you pull straight down on the rope? Neglect the pulley system's mass. |:|N Additional Maten'als 5. [-H Points] DETAILS OSCOLPHY52016 9.6.P.031. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER We analyzed the biceps muscle example with the angle between forearm and upper arm set at 90D (see gure below}. Triceps Find the force exerted by the biceps muscle when the angle is 115 and the forearm is in a downward position. [Assume that r1 = 3.0 cm, r2 ma = 3.0 kg, and mb = 4.2 kg. Enter the magnitude.) |:|N 'l' = 14 cm,r 3 = 36 cm, 6. [-/1 Points] DETAILS OSCOLPHYS2016 10.1.P.001. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER At its peak, a tornado is 50.0 m in diameter and carries 460 km/h winds. What is its angular velocity in revolutions per second? rev/s Additional Materials Reading 7. [-/4 Points] DETAILS OSCOLPHYS2016 10.1.P.002. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER An ultracentrifuge accelerates from rest to 100,000 rpm in 3.50 min. (a) What is its angular acceleration in rad/s? rad/s2 (b) What is the tangential acceleration (in m/s ) of a point 9.50 cm from the axis of rotation? m/s2 (c) What is the radial acceleration in m/s and multiples of g of this point at full rpm? a in m/s m/s2 a as a multiple of g8. [-/2 Points] DETAILS OSCOLPHYS2016 10.2.P.005. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER With the aid of a string, a gyroscope is accelerated from rest to 41 rad/s in 0.53 s. (a) What is its angular acceleration in rad/s? rad/s2 (b) How many revolutions does it go through in the process? rev Additional Materials Reading 9. [-/4 Points] DETAILS OSCOLPHYS2016 10.2.XP.001. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER (a) Calculate the linear acceleration (in m/s2) of a car, the 0.290 m radius tires of which have an angular acceleration of 7.0 rad/s'. Assume no slippage. m/s2 (b) How many revolutions do the tires make in 2.50 s if they start from rest? rev (c) What is their final angular velocity (in rad/s)? rad/s (d) What is the final velocity (in m/s) of the car? m/s10. [-f1 Points] DETAILS OSCOLPHY5201610.4.WA.030. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A typical helicopter with four blades rotates at 370 rpm and has a kinetic energyr of 2.85 x 105 J. What is the total moment of inertia, in kg - m2 of the blades? E kg - m2 Additional Materials in Reading 11. [i2 Points] DETAILS OSCOLPHYSZO1610.5.P.036. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER (a) Calculate the angular momentum (in kg - mzx's) of Saturn in its orbit around the Sun. (The mass of Saturn is 5.680 x 1026 kg, the orbital radius is 1.427 x 109 km and the orbital period is 29.5 y.) E kg - m2... (b) Compare this angular momentum with the angular momentum of Saturn on its axis. [The radius of Saturn is 6.02? x 104 km and the rotation period is 10.66 h.) Lrotation 12. [-/3 Points] DETAILS OSCOLPHYS2016 10.5.P.041. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER (a) Calculate the angular momentum (in kg.m) of an ice skater spinning at 6.00 rev/s given his moment of inertia is 0.470 kg.m-. kg.m /'s (b) He reduces his rate of spin (his angular velocity) by extending his arms and increasing his moment of inertia. Find the value of his moment of inertia (in kg.m-) if his angular velocity drops to 2.05 rev/s. kg.m2 (c) Suppose instead he keeps his arms in and allows friction with the ice to slow him to 3.00 rev/s. What average torque (in N.m) was exerted if this takes 18.0 seconds? N.m Additional Materials Reading13. [-1'2 Points] DETAILS OSCOLPHY5201610.5.WA.054. NOTES ASK YOUR TEACHER PRACTICE ANOTHER The diagram shows a thin rod of uniform mass distribution pivoted about one end by a pin passing through that point. The mass of the rod is 0.300 kg and its length is 2.90 m. When the rod is released from its horizontal position, it swings down to the vertical position as shown. b T M L .cc/ (a) (a) Determine the speed of its center of gravityr at its lowest position in m/s. E m (b) When the rod reaches the vertical position, calculate the tangential speed of the free end of the rod in mfs. E m