Quiz Test-3 Select the True of False? 1. When objects rest on a non-accelerating horizontal surface, the magnitude of the normal force is equal to the weight of the object: N= mg True False 2. When objects rest on an inclined plane that makes an angle 0 with the horizontal surface, the weight of the object can be resolved into components that act perpendicular (wl) and parallel (wll) to the surface of the plane. These components can be calculated using: wll= w sin (0)= wmgsin(0) wl=w cos(0)= mgcos(0). True False 3. The pulling force that acts along a stretched flexible connector, such as a rope or cable, is called tension, T. When a rope supports the weight of an object that is at rest, the tension in the rope is equal to the weight of the object: T=mg. True False 4. The normal force on an object is not always equal in magnitude to the weight of the object. If an object is accelerating, the normal force will be less than or greater than the weight of the object. Also, if the object is on an inclined plane, the normal force will always be less than the full weight of the object. True False 5. The tendency of an object to remain at rest or remain in motion is called friction. True False 6. Free-fall is a situation in which the only force acting on an object is the force due to gravity and is called inertia called Newton's 1st law of motion. True False 7. Mass is the quantity of matter in a substance; in kilograms, which is wrongly called weight. True False 8. Hook's Law provides the proportional relationship between the force F on a material and the deformation AL it causes, F=KAL, k being constant of [roportionality. True False 9. The static friction is a force that opposes the motion of two systems that are in contact and are not moving relative to one another while in motion the magnitude of kinetic friction is given by fk = HKN, where /k is the coefficient of kinetic friction True False 10. The magnitude of static friction is given by fs S UsN, where Asis the coefficient of static friction and N is the magnitude of the normal force. True FalseQuiz Test4 Select the True of False? 1.5train is the ratio of change in length to original length while Stress is the ratio of force to area True False 2. Uniform circular motion is motion in a circle at constant speed. The rotation angle AB is dened as the ratio of the arc length to the radius of curvature: nB=As/r, where arc length as is distance traveled along a circular path and r is the radius of curvature of the circular path. True False 3. From radians to degree, we use 211 rad:3609 the conversion between radians and degrees is lrad=25?.39 True False 4. Angular velocity u: is the rate of change of an angle, m:AB/'At, The units of angular velocity are radians per second {rad/s]. True False 5. Linear velocity v and angular velocity in are related by (13:71: True False 6. Centripetal acceleration :1C is the acceleration experienced while in uniform circular motion It always points toward the center of rotation. It is 2 perpendicularto the linear velocity v and has the magnitude of = v: or a: = 11.02 True False 7. the point where the entire mass of an object or ofa system of objects can be thought to be concentrated is called center of mass True False 8. Centripetal force F: is any force causing uniform circular motion. It is a \"center seeking\" force that always points toward the center of rotation. It is perpendicular to linear velocity 17 and has magnitude 5. = 111er True False 9. The centrifugal force a fictitious force that tends to throw an object off when the object is rotating in a non-inertial frame of reference. A ctitious force is a force having no physical origin True False 10. : Newton's Universal Law of Gravitation states that every particle in the universe attracts every other particle with a force along a line joining them. The force is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. In equation form, this is GmM F : Z consternt, given by 6:6.674x10'\" N'mzlkg2 True False 11. The Kepler's 2nd law states that the orbit of each planet about the Sun is an ellipse with the Sun at one focus, while Kepler's 1St law states that Each planet moves so that an imaginary line drawn from the Sun to the planet sweeps out whe re F is the magnitude of the gravitational force. (3 is the gravitational equal areas in equal times. True False 12. The ratio of the squares of the periods of any two planets about the Sun is Z 3 equal to the ratio of the cubes of their average distances from the Sun: :42 = :43 2 2 Where Tis the period [time for one orbit) and r is the average radius of the orbit. The period and radius of a satellite's orbit about a larger body M are related by r3 \":2 c 2, 3 _: T GMT,Or r2 M2M