hii can you answer each question with explanation. Because I have no clue how to do them thanks. They are 19 questions
desi Name: Stay and e a) What is the maximum acceleration of the blocks before the top block begins to slide off the bottom block? (Hint: Draw the free body diagram of the top block and determine the acceleration when the coefficient of static friction is at its max value of 0.75 and the top block is at rest relative to the bottom block) b) What is the maximum horizontal Force, F, that can be exerted on the lower block before the top block begins to slide off? (Hint: Draw the free body diagram of the bottom block and apply Newtons 2nd law to the bottom block) cesar16. A system of two blocks is accelerated by an applied force of magnitude F on a frictionless For need .horizontal surface. cergraton m 3m a) What is the acceleration of the blocks in terms of m and F? b) What is the tension in the string between the blocks in terms of F? c) If m = 3 kg and the applied force were 48 N, what is the acceleration of the blocks? d) What is the tension in the string between the blocks? 17. A stack of boxes are in an elevator that is at rest as shown at right. The masses of the boxes are given in terms of M. V = 0 a) How does the magnitude of force the top block exerts on the bottom compare with the force the bottom block exerts on the top? b) Draw and label a quantitative force diagram for each block using hatch marks on the vectors to show equalities M 3M M M SIV 3M c) What is the magnitude of the force the bottom box exerts on the top box in terms of M and g? 17. A stack of boxes are in an elevator that is accelerating upwards. The masses of the boxes are given in terms of M. a) How does the magnitude of force the top block exerts on the bottom a compare with the force the bottom block exerts on the top? b) Draw and label a quantitative force diagram for each block using hatch M marks on the vectors to show equalities 3Mver. g desig Name: a M 3M 3M TWO Glocks is securerated by airapplied force wild c) What is the magnitude of the force the bottom box exerts on the top box in terms of M, a and g? 18. Two blocks of mass mi = 2 kg and mass m2 = 7 kg are wedged up against one another and against a wall by a horizontal force F. Solve each part just using the variables to get an expression for the unknown in terms of variables before plugging in wall m numbers. m2 a) What is the coefficient of static friction between ml and m2 (call F this s1) and between m2 and the wall (call this $2) if the MINIMUM force Fmin required to keep the blocks from breaking loose and sliding under the influence of gravity is Fmin = 25 N? b) The force F is decreased to 20 N. The blocks break loose and begin to fall. If the coefficient of kinetic friction between ml and m2 AND between m2 and the wall are kl = 0.15 and k2 = 0.9 respectively, what are the accelerations of ml and m2? Note that they will not be the same. c) Why are the accelerations different? 19. (Very Challenging) A man drags a 100 kg crate up the ramp of a truck. The ramp is inclined at 20 and the man pulls at an angle of 30 above the ramp. The coefficient of friction between the crate and the ramp is 0.2. a) What is the normal force on the crate in terms of the applied force, F? (Hint: The normal force does not just balance the perpendicular component of gravity) b) What is the minimum force the man would have to apply to pull the crate up the ramp (Hint: minimum force would be the force required to pull the crate up the ramp at constant velocity) 20.00-ca Name: duct box 2-body (and friction and incline) problems Check simulation of any 2 object system (http://ophysics.com/f3.html); it will really help you check your FDBs and you will get a better understanding of what is happening. Remember, you can solve these problems with multiple objects in two ways: a) Draw FDBs and apply Newton's 2"d Law to each object in order to get a system of equations that can be used to solve for multiple unknowns. In solving the problem in this way it is really important to remember that for each object the + direction is chosen in the direction of the acceleration of the object. b) Treat the multiple objects as part of one SYSTEM and apply Newtons 2"" Law to the system in order to find the acceleration of the system or the value of an external force (remember that the only forces acting on the system are the external forces; forces internal to the system cancel out and therefore do not need to be considered). To determine the values of any internal forces, each object must be considered separately. eminnu chagram for the woman 9. At right is a picture of an Atwood's machine: two masses attached to a fer worth frictionless, massless pulley. The mass of block A is 5.0 kg and the mass of rent weight? (mal aret by the qoymal block B is 2.0 kg. how decelerates mist. Constru a) What is the acceleration of the system when the blocks are released? What is the tension in the string? b) How long will it take for block A to fall 2.0 m? 10. a) mi = 5 kg and m2 - 8 kg. A block of mass mi is on a ramp that is inclined at 20 above the horizontal. It is connected by a string to a block of mass m2 that hangs over the top edge of the ramp. The m1 19 coefficient of kinetic friction between the incline and the ml block is 2 0.22. What is the acceleration of the masses and the tension in the 20 string'? - - - - - - b) If mi = 8 kg, and the coefficient of static friction between mi and the incline is 0.300, find the maximum value of ma that will not make mi slide up the incline (ie. when static friction is maximum). 1 1. In the diagram at right, ma has a mass of 20.0 kg. There is friction on the incline. Static friction can exert a maximum force of 30.0 N on m2. This my friction can act up or down the incline, depending on the value of mi. a) If mi is heavy enough, m2 will start to accelerate up the incline. What is the maximum value mi can have without 0 = 20' m1 m2 sliding up the incline? ( b) If mi is light enough, ma will start to accelerate down the incline. What is the minimum value mi can have without m2 sliding down the incline. (static friction is not in the same direction as part a)) (use Mr. Walsh's simulation to check your work, check your FDB and to get a better understanding of the problem)and ente Name: 2 1 3 12. If mass #1 = 2 kg, mass #2 = 4 kg, and mass # 3 = 6 kg, find the acceleration of the three masses, and the internal tension in each string. The pulleys are frictionless, but the coefficient of kinetic friction between the plane and block 2 is 0.400. woman's 2 20 40 13. If both masses above equal 3 kg, find the acceleration of the two masses, and the tension in the string. The 40 incline is frictionless, but the 20 incline has a coefficient of kinetic friction of 0.100 14. In the figure to the right, two boxes of masses 2m and 5m are in contact with each other on a frictionless surface. A force, F, is applied to 2m. Answers to the following questions should be in terms of F and m a) What is the acceleration of the more massive box? b) What is the force causing the acceleration of the more massive box (the net force on 5m)? F 45m c) What is the force exerted on the smaller box by the larger box? Pn d) What is the net force on the smaller box? e) Show all the forces acting on each box below. Indicate the action reaction pairs of forces for all the forces acting on the boxes. 5m 2m 2m 5m f) Answer parts a)-d) if there is friction between the blocks and the table and the coefficient of kinetic friction is k. Answers should be in terms of F, m, k and g 15. This arrangement is being pulled across the floor. The coefficient of kinetic friction between the larger block and the floor is (0.50). The coefficient of static friction between the two blocks is (0.75). (Note that the weight, not the mass, of each block is given) 30N 100N -FForces and Laws of Motion Friction, Inclines and Multi-Body Problems Do these problems on separate sheets of paper. For each of the problems below, you must begin your solution with a clear, accurate free body diagram. Show your solutions step by step starting with the basic conceptual equation (Newton's 2"d Law). Compute the size of the initial upward acceleration of a rocket of mass 1.30 x 10" kg if the initial upward thrust of its engine is 2.60 x 10" N. Do not neglect the weight of the rocket. Construct the force diagram 2. A 60 kg woman stands in an elevator that is accelerating downward at 3.10 m/s2. a) Construct the force diagram for the woman b) What is her weight? c) What is her apparent weight? (measured by the normal force acting on her) d) The elevator now accelerates up at 3.10 m/s . Construct the force diagram and determine the woman's apparent weight. 3. The maximum force that a grocery bag can withstand without ripping is 250 N. Suppose that bag is filled with 20.0 kg of groceries and lifted with an acceleration of 5.0 m/s . Do the groceries stay in the bag? Friction Practice problems (1 object) Check simulations of friction on a horizontal surface (http://ophysics.com/f1.html ) and on an incline (http://ophysics.com/f2.html); you will get better understanding and you can check your work. 4. A shuffleboard disk is accelerated to a speed of 5.8 m/s and released. If the coefficient of kinetic friction between the disk and the concrete court is 0.31, how far does the disk go before it comes to a stop? The courts are 15.8 m long. F ensio 5. A 15.0 kg box is being pulled along level ground by a 75.0 N force pull that is directed at an angle of 20 above the horizontal. The 20 coefficient of kinetic friction is 0.330. What is the acceleration of the box? 6. Stacie, who has a mass of 45 kg, starts down a slide that is inclined at an angle of 450 with the horizontal. If the coefficient of kinetic friction between Stacie's shorts and the slide is 0.25, what is her acceleration? Try to first derive an expression for a in terms of the given variables (q, k, g). 7. A 63-kg water skier is pulled at a constant speed up a 14.0 incline by a rope parallel to the incline with a tension of 31 1 N. a) What is the coefficient of kinetic friction between the skis and the incline? b) If the tension in the rope were increased to 511 N, determine the acceleration of the skier. 8. A block is set on an adjustable ramp and the angle of incline is increased slowly until the block is observed to start sliding when the angle is q. (a) Determine the coefficient of static friction, us, in terms of the maximum angle of incline, 0, at which the block can remain at rest on the ramp. (b) Considering the fact that us is almost always less than or equal to one, at what amount of incline would there be too o little friction to prevent virtually anything from sliding
