Concept explainers
Starting from rest, a rectangular toy block with mass 300 g slides in 1.30 s all the way across a table 1.20 m in length that Zak has tilted at an angle of 42.0° to the horizontal. a. What is the magnitude of the acceleration of the toy block? b. What is the coefficient of kinetic friction between the block and the table? c. What are the magnitude and direction of the friction force acting on the block? d. What is the speed of the block when it is at the end of the table, having slid a distance of 1.20 m?
(a)
Find the magnitude of acceleration of the toy block.
Answer to Problem 74PQ
The magnitude of acceleration of the toy block is
Explanation of Solution
Write the equation for acceleration.
Here,
Conclusion:
Substitute
Therefore, the magnitude of acceleration of the toy block is
(b)
Find the coefficient of kinetic friction between the block and table.
Answer to Problem 74PQ
The coefficient of kinetic friction between the block and table is
Explanation of Solution
From the given condition the free body diagram is given below.
Here,
Here,
Write the equation for friction force.
Here,
Substitute equation II and III in equation IV.
Conclusion:
Substitute
Therefore, the coefficient of kinetic friction between the block and table is
(c)
Find the direction and magnitude of friction acting on the block.
Answer to Problem 74PQ
The friction acting on the block is directed upward and its magnitude is
Explanation of Solution
Substitute equation III in IV.
Conclusion:
Substitute
The friction force is directed up in the incline.
Therefore, the friction acting on the block is directed upward and its magnitude is
(d)
Find the speed of the block when it is at the end of the table.
Answer to Problem 74PQ
The speed of the block when it is at the end of the table is
Explanation of Solution
Write the equation of motion.
Here,
Conclusion:
Substitute
Therefore, the speed of the block when it is at the end of the table is
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Chapter 5 Solutions
Student Solutions Manual For Katz's Physics For Scientists And Engineers: Foundations And Connections, Volume 1
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