Question 1A wheel from rest is to reach and angular velocity of 100 rad/s in 20s. What angular acceleration must it have and what is its angle turned through in at that given time? Selected Answer: 5 rad/s2, 1000 rad Question 2 A car is traveling at 50 km/hr on a road such that the coefficient of friction between its tires and the road is 0.70. The minimum turning radius of the car is Selected Answer: 28 m Question 3 A large tank holding oil 5 meters deep breaks, opening a hole at the bottom. What is the speed of the oil emerging from the hole? Selected Answer: 9.90 m/s Question 4 A 40-N block slides down a board with constant speed when the angle of elevation is 30°. Which of the following is not true for this situation? Selected Answer: Fk = 34.6 N Question 5 Which of the following is true about the x-component of a projectile? Selected Answer: Velocity varies. Question 6 A projectile is thrown from the top of a building with an initial velocity of 30 m/s in the horizontal direction. If the top of the building is 30 m above the ground, how fast will the projectile be moving just before it strikes the ground? Selected Answer: 39 m/s Question 7 Car A has a mass of 1000 kg and a speed of 30 m/s. Car B has a mass of 2000 kg and a speed of 15 m/s. The kinetic energy of car A is Selected Answer: twice that of car B. Question 8 A ball is kicked into the air from the surface of a playing field. If friction is negligible, the ball will follow a path that is Selected Answer: parabolic. Question 9 Given two concurrent forces: F1= 150kN 30° N of E and F2= 280kN 70° S of W. Calculate the magnitude and direction of the resultant. Selected Answer: 191.19 kN; 79.71° S of E Question 10 The position coordinate of a particle which is confined to move along a straight line is given by s=2t 3 - 24t +6 where s is measured in meters from a convenient origin and where t is in seconds. Which of the following gives the time required for the particle to reach a velocity of 72 m/s? Selected Answer: 4 sec Question 11 A torque can be exerted on a body with a fixed axis of rotation Selected Answer: only by a tangential force. Question 12 You want to throw a ball straight up into the air so that it reaches a height of 4.5 m above the ground. Ignore any effects of air resistance. If the ball leaves your hand at a height of 1.2 m above the ground, how fast do you need to throw it? Selected Answer: 8 m/s Question 13 A ball at the end of a 50 cm string is being whirled in a vertical circle. At what critical velocity will the string begin to slack at the top of the ball’s path? Selected Answer: 2.21 m/s Question 14 A 1200kg elevator is supported by a cable in which the maximum safe tension is 14kN. What is the greatest upward acceleration of the elevator? Selected Answer: 1.87 m/s2 Question 15 When a force of 80 N is applied to a spring, it elongates 0.50 m. Determine the period of oscillation of a 6 kg object suspended from this spring. Selected Answer: 1.217 sec Question 16 If C = [10 m, 30°] and D = [25 m, 130°], what is the direction of the sum of these two vectors? Selected Answer: 107° Question 17 Which of the law describes Newton’s First Law of Motion? Newton’s Three Laws of Motion I. For every action there is an equal and opposite reaction. II. The total amount of energy in an isolated system remains constant over time (is said to be conserved over time). III. The relationship between an object's mass m, its acceleration a, and the applied force F is F = ma. Acceleration and force are vectors (as indicated by their symbols being displayed in slant bold font); in this law the direction of the force vector is the same as the direction of the acceleration vector. IV. Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it. Selected Answer: IV Question 18 How much water in m3 will escape per hour from an open-top tank through an opening 5 cm in diameter that is 5m below the water level in the tank. Selected Answer: 68.4 m3 Question 19 A hiker walks 53.1 degrees north of east for 2.5 km then due east for 2.0 km. What is her total displacement from her starting point if you measure the distance along a straight line? Selected Answer: 4.03 km Question 20 Water is flowing at 2.5 meters per second in a pipe 5 centimeters in diameter. A section of the pipe narrows to 3 centimeters. How fast is the flow in the narrow section? Selected Answer: 7 m/s Question 21 Which of the following correctly states Newton's third law of motion? Forces occur in matched pairs that are Selected Answer: equal in magnitude and opposite in direction. Question 22 Find the moment of inertia of a solid sphere of mass 10 kg and radius 0.4 m about an axis tangent to the sphere. (ICG = 0.4 MR2) Selected Answer: 2.24 kg-m2 Question 23 The following are consequences of the Continuity Equation EXCEPT Selected Answer: water pressure Question 24 A cable has a cross-sectional area of 5 cm2. It will break if subjected to a tensile stress greater than 1 x 108 Pa. How much force must be applied to the cable in order to break it? Selected Answer: 5 x 104 N Question 25 Which of the following is a statement of Pascal's law? Selected Pressure applied to an enclosed fluid is transmitted undiminished to every portion of Answer: the fluid and to the walls of the container. Question 26 A rock is suspended from a gram-calibrated spring scale, which reads 120 grams when the rock is in air and 90 grams when it is in water. What is the density of the rock? Selected Answer: 1.5 g/cm3 Question 27 If a road is banked, at what banking angle Θ can the car make the turn without depending on friction? Selected Answer: tan-1(v2/gr) Question 28 How long should a pendulum be if it is to have a period of one second at a place on Earth where the acceleration due to gravity is 9.81m/s2? Selected Answer: 0.248 m Question 29 A submarine weighing 550 kN has 3 people on board weighing 70kg each. The submarine has a volume of 70 m3 and will be submerged in fluid of S.G.=1.2. Find the minimum weight of the ballast required to bring the submarine down the fluid. Neglect hydrostatic pressure. (Use g=9.8 m/s 2.) Selected Answer: 552058 N Question 30 A 100g object is suspended from a spring whose force constant is 50N/m. What is the period of oscillation of the system? Selected Answer: 0.281 s