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
Want to see more full solutions like this?
Chapter 5 Solutions
EBK WEBASSIGN FOR KATZ'S PHYSICS FOR SC
- A pail of water is rotated in a vertical circle of radius 1.00 m. (a) What two external forces act on the water in the pail? (b) Which of the two forces is most important in causing the water to move in a circle? (c) What is the pails minimum speed at the top of the circle if no water is to spill out? (d) If the pail with the speed found in part (c) were to suddenly disappear at the top of the circle, describe the subsequent motion of the water. Would it differ from the motion of a projectile?arrow_forwardA hockey stick pushes a 0.160-kg puck with constant force across the frictionless surface of an ice rink. During this motion, the pucks velocity changes from 4.00 m/s to (6.00 + 12.00) m/s in 4.00 s. a. What are the scalar components of the force acting on the puck? b. What is the magnitude of the force acting on the puck?arrow_forward(a) A cat with a mass of 850 kg in moving to the right with a constant speed of 1.44 m/s. What is the total force on the cat ? (b) What is the total force on the cat if it is moving to the left?arrow_forward
- A pail of water is rotated in a vertical circle of radius 1.00 m. (a) What two external forces act on the water in the pail? (b) Which of the two forces is most important in causing the water to move in a circle? (c) What is the pails minimum speed at the top of the circle if no water is to spill out? (d) Assume the pail with the speed found in part (c) were to suddenly disappear at the top of the circle. Describe the subsequent motion of the water. Would it differ from the motion of a projectile?arrow_forwardA. What is the tension in the lower cord? B. What is the speed of the block? V= m/sarrow_forward3. You push a grocery cart along a level floor in the presence of friction effects between the cart and the floor. a. Draw force diagrams for you, the cart, and the floor/earth. Fully label all vectors. b. While you are making the cart speed up, how does the size of the force you apply on the cart b. compare to the size of the force the cart exerts on you? Explain. c. While you are making the cart speed up, how does the size of the frictional force on the cart by the floor compare to the frictional force on you by the floor?arrow_forward
- Starting from rest, an elevator weighing 9000 Newtons attains an upward velocity of 5 m/s in 4 seconds with uniform acceleration. a. Compute for the uniform acceleration. b. Compute the apparent weight of a man weighing 600 Newtons standing inside the elevator during the accent. c. Compute the tension in the supporting cable of the elevator.arrow_forwardA stuntman drives a car of mass 1125 kg east with a speed of 20 m/s. a. If the car accelerates at a rate of –2 m/s 2 , how long will it take the car to go 50 m? b. The stuntman drives the car off an 80 m cliff while going 15 m/s. How long will it take the car to land? c. How far horizontally from the cliff will the car land?arrow_forwardA bullet is fired vertically downward into a uniform soil medium with an initial velocity of 50 m/s. Due to drag resistance of the uniform soil the bullet experiences a deceleration of a = -0.20 m/s2 . a. What is the bullet velocity in m/s 4 seconds after it is fired? b. What is the bullet position in meters 4 seconds after it is fired? c. What is the bullet velocity in m/s 2 seconds after it is fired, if the initial velocity is increase to 60 m/s? d. What is the bullet position in meters 2 seconds after it is fired, if the initial velocity is increase to 60 m/sarrow_forward
- a. What is the magnitude of acceleration of the block? b. What is the magnitude of the tension force from the block on the cylinder?arrow_forwardYour forehead can withstand a force of about 6.0 kN before fracturing, while your cheekbone can only withstand about 1.3 kN. a. If a 140 g baseball strikes your head at 30 m/s and stops in 0.0015 s, what is the magnitude of the ball’s acceleration? b. What is the magnitude of the force that stops the baseball? c. What force does the baseball apply to your head? Explain. d. Are you in danger of a fracture if the ball hits you in the forehead? In the cheek?arrow_forwardA friction experiment is performed on a planet that has the same size as Earth but half the mass. A 1.0-kg block is pulled along a horizontal dynamics track with a horizontal force of magnitude 15.0 N. If the coefficient of kinetic friction between the block and the track is 0.3. determine the acceleration of the block. O a. 2.94 m/s^2 O b.3.24 m/s^2 O c. 9.12 m/s^2 O d. 13.53 m/s^2arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningCollege PhysicsPhysicsISBN:9781305952300Author: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, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning