Stuart Clark PHYS 1401 Module 4 Exam 1 What is the angular speed and rad s of the second hand of a watch A B C D E 1 7 x 10 3 rad s 0 10 rad s 0 02 rad s 6 28 rad s 60 rad s 2 An airplane engine starts from rest and 2 seconds later it is rotating with an angular speed of 420 rev min If the angular acceleration is constant how many revolutions does the propeller undergo during this time A B C D E 7 14 21 49 150 3 A satellite follows a circular path with constant speed around a planet Which of the following quantities is constant and non zero for this satellite A B C D E Linear velocity Angular velocity Centripetal acceleration Angular acceleration Total acceleration 4 Complete the following statement When a net torque is applied to a rigid object it always produces a A B C D E Constant acceleration Rotational equilibrium Constant angular velocity Constant angular momentum Change in angular velocity 5 Complete the following statement A body is in translational equilibrium A B C D E Only if it s at rest Only if its moving with constant velocity Only if its moving with constant acceleration If it s either at rest or moving with constant velocity If it s moving with either constant velocity or constant acceleration 6 Consider the following four objects a hoop a flat disk a solid sphere and a hollow sphere Each of the objects has mass M and radius R The axis of rotation passes through the center of each object and is perpendicular to the plane of the hoop and the plane of the flat disk Which object requires the largest torque to give it the same angular acceleration A B C D E The solid sphere The hollow sphere The hoop The flat disk Both the solid and the hollow spheres 7 A child wants to pump up a bicycle tire so that its pressure is 1 2 105 Pa above that of atmospheric pressure If the child uses a pump with a circular piston 0 035 m in diameter what force must the child exert A B C D E 120 N 89 N 76 N 54 N 240 N 8 The two dams are identical with the exception that the water reservoir behind dam A extends twice the horizontal distance behind it as that of dam B Which one of the following statements regarding these dams is correct A B C D E The force exerted by the water on dam A is greater than that on dam B The force exerted by the water on dam B is greater than that on dam A Dam A is more likely to collapse than dam B if the water level rises Dam B is more likely to collapse than dam A if the water level rises The horizontal distance of the water behind the two dams does not determine the force on them 9 Complete the following sentence The operation of a hydraulic jack is an application of A B C D E Pascal s principle Bernoulli s principle Archimedes principle Irrotational flow The continuity equation 10 Which one of the following statements concerning buoyant force on an object submerged in a liquid is true A B C D E The buoyant force depends on the mass of the object The buoyant force depends on the weight of the object The buoyant force is independent of the density of the liquid The buoyant force depends on the volume of the liquid displaced The buoyant force will increase with depth if the liquid is incompressible 11 A curtain hangs straight down in front of an open window A sudden gust of wind blows past the window and the curtain is pulled out of the window Which law principle or equation can be used to explain this movement of the curtain A Poiseuille s law B Bernoulli s principle C The equation of continuity D Archimedes principle E Pascal s principle 12 A baseball pitcher throws the ball in a motion where there is rotation of the forearm about the elbow joint as well as other movements If the linear velocity of the ball relative to the elbow joint is 10 0 m s at a distance of 0 410 m from the joint and the moment of inertia of the forearm is 0 500 kg m2 what is the rotational kinetic energy of the forearm in Joules A 148 72 13 Suppose you have a coffee mug with a circular cross section and vertical sides What is its inside radius if it holds 400 0 g of coffee when it s filled to a depth of 6 00 cm Assume coffee has the same density of water Answer in cm B 4 6 cm 14 What force N must be exerted on the master cylinder of a hydraulic lift to support the weight of a 2300 0 kg car resting on the slave cylinder The master cylinder has a 1 70 cm diameter while the slave s is 24 0 cm C 113 2 15 Hoover Dam generates electricity with water taken from a depth of 100 0 m and with an average flow rate of 6 20 x 102 m3 s Calculate the power in this flow in watts A 6 08 x 108