Concept explainers
Two forces
Figure P4.7
(a)
The acceleration of the object.
Answer to Problem 7P
The acceleration of the object is
Explanation of Solution
Write the expression for net force.
Here,
Write the expression for acceleration by using equation (I).
Here,
Write the expression for the direction of the acceleration.
Here,
Write the expression for the magnitude of the acceleration.
Here,
Conclusion:
Substitute,
Substitute,
Substitute,
Thus, the acceleration of the object is
(b)
The acceleration of the object.
Answer to Problem 7P
The acceleration of the object is
Explanation of Solution
Write the expression for net force.
Here,
Write the expression for acceleration by using equation (I).
Here,
Write the expression for the direction of the acceleration.
Here,
Write the expression for the magnitude of the acceleration.
Here,
Conclusion:
Substitute,
Substitute,
Substitute,
Thus, the acceleration of the object is
Want to see more full solutions like this?
Chapter 4 Solutions
Principles of Physics: A Calculus-Based Text
- Two blocks of mass 3.50 kg and 8.00 kg are connected by a massless string that passes over a frictionless pulley (Fig. P4.47). The inclines are frictionless. Find (a) the magnitude of the acceleration of each block and (b) the tension in the string. Figure P4.47arrow_forwardTwo objects, m1 = 3.00 kg and m2 = 8.50 kg, are attached by a massless cord passing over a frictionless pulley as shown in Figure P5.51. Assume the horizontal surface is frictionless. a. Draw a free-body diagram for each of the two objects. b. What is the tension in the cord? c. What is the magnitude of the acceleration of the two objects? FIGURE P5.51 Problems 51 and 65.arrow_forwardA 276-kg glider is being pulled by a 1 950-kg jet along a horizontal runway with an acceleration of a = 2.20 m/s2 to the right as in Figure P4.41. Find (a) the thrust provided by the jets engines and (b) the magnitude of the tension in the cable connecting the jet and glider. Figure P4.41arrow_forward
- Figure P4.26 shows loads hanging from the ceiling of an elevator that is moving at constant velocity. Find the tension in each of the three strands of cord supporting each load. Figure P4.26arrow_forwardA block of mass m = 5.8 kg is pulled up a = 25 incline as in Figure P4.24 with a force of magnitude F = 32 N. (a) Find the acceleration of the bloc k if the incline is frictionless. (b) Find the acceleration of the block if the coefficient of kinetic friction between the block and incline is 0.10. Figure P4.24arrow_forwardIn Example 4.5, we pushed on two blocks on a table. Suppose three blocks are in contact with one another on a frictionless, horizontal surface as shown in Figure P4.49. A horizontal force F is applied to m1. Take m1 = 2.00 kg, m2 = 3.00 kg, m3 = 4.00 kg, and F = 18.0 N. (a) Draw a separate free-body diagram for each block. (b) Determine the acceleration of the blocks. (c) Find the resultant force on each block. (d) Find the magnitudes of the contact forces between the blocks. (e) You are working on a construction project. A coworker is nailing up plasterboard on one side of a light partition, and you are on the opposite side, providing backing by leaning against the wall with your back pushing on it. Every hammer blow makes your back sting. The supervisor helps you put a heavy block of wood between the wall and your back. Using the situation analyzed in parts (a) through (d) as a model, explain how this change works to make your job more comfortable. Figure P4.49arrow_forward
- Two blocks are connected by a rope that passes over a massless and frictionless pulley as shown in Figure P5.41. Given that m0 = 15.93 kg and m2 = 10.45 kg, determine the magnitudes of the tension in the rope and the blocks acceleration. FIGURE P5.41arrow_forwardA car accelerates down a hill (Fig. P4.57), going from rest to 30.0 m/s in 6.00 s. A toy inside the car hangs by a string from the cars ceiling. The ball in the figure represents the toy, of mass 0.100 kg. The acceleration is such that the string remains perpendicular to the ceiling. Determine (a) the angle and (b) the tension in the string. Figure P4.57arrow_forwardTwo blocks, each of mass m, are hung from the ceiling of an elevator as in Figure P4.33. The elevator has an upward acceleration a. The strings have negligible mass. (a) Find the tensions T1 and T2 in the upper and lower strings in terms of m, a, and g. (b) Compare the two tensions and determine which string would break first if a is made sufficiently large. (c) What are the tensions if the cable supporting the elevator breaks? Figure P4.33 Problems 33 and 34.arrow_forward
- In Figure P4.35, the man and the platform together weigh 950 N. The pulley can be modeled as frictionless. Determine how hard the man has to pull on the rope to lift himself steadily upward above the ground. (Or is it impossible? If so, explain why.) Figure P4.35arrow_forwardTwo objects are connected by a light string that passes over a frictionless pulley as shown in Figure P4.30. Assume the incline is frictionless and take m1 = 2.00 kg, m2 = 6.00 kg, and = 55.0. (a) Draw free-body diagrams of both objects. Find (b) the magnitude of the acceleration of the objects, (c) the tension in the string, and (d) the speed of each object 2.00 s after it is released from rest. Figure P4.30arrow_forwardA block of mass m = 5.8 kg is pulled up a = 25 incline as in Figure P4.24 with a force of magnitude F = 32 N. (a) Find the acceleration of the bloc k if the incline is frictionless. (b) Find the acceleration of the block if the coefficient of kinetic friction between the block and incline is 0.10. Figure P4.24arrow_forward
- College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning