Concept explainers
A solid ball is released from rest and slides down a hill-side that slopes downward at 65.0° from the horizontal. (a) What minimum value must the coefficient of static friction between the hill and ball surfaces have for no slipping to occur? (b) Would the coefficient of friction calculated in part (a) be sufficient to prevent a hollow ball (such as a soccer ball) from slipping? Justify your answer. (c) In part (a), why did we use the coefficient of static friction and not the coefficient of kinetic friction?
Want to see the full answer?
Check out a sample textbook solutionChapter 10 Solutions
University Physics (14th Edition)
Additional Science Textbook Solutions
Life in the Universe (4th Edition)
Sears And Zemansky's University Physics With Modern Physics
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)
College Physics: A Strategic Approach (4th Edition)
Conceptual Physical Science (6th Edition)
Lecture- Tutorials for Introductory Astronomy
- A solid ball is released from rest and slides down a hillside that slopes downward at 65.0° from the horizontal. (a) What minimum value must the coefficient of static friction between the hill and ball surfaces have for no slipping to occur? (b) Would the coefficient of friction calculated in part (a) be sufficient to prevent a hollow ball (such as a soccer ball) from slipping? Justify your answer. (c) In part (a), why did we use the coefficient of static friction and not the coefficient of kinetic friction?arrow_forwardCalculate the horizontal force P on the light 13° wedge necessary to initiate movement of the 59-kg cylinder. The coefficient of static friction for both pairs of contacting surfaces is 0.33. Also determine the friction force Få at point B. (Caution: Check carefully your assumption of where slipping occurs.) P Answers: P = FB = i 138 59 kg B N N Aarrow_forwardA horizontal force of 170 N is required to push a 180-kg refrigerator across a level linoleum floor. The refrigerator rolls on four 50-mm-diameter plastic wheels. Neglect all friction except rolling resistance and determine the coefficient of rolling friction between the plastic wheels and the linoleum floor.arrow_forward
- A uniform cube of side length 8.0 cm rests on a horizontal floor.The coefficient of static friction between cube and floor is m. A horizontal pull is applied perpendicular to one of the vertical faces of the cube, at a distance 7.0 cm above the floor on the vertical midline of the cube face. The magnitude of is gradually increased. During that increase, for what values of m will the cube eventually (a) begin to slide and (b) begin to tip? (Hint: At the onset of tipping, where is the normal force located?)arrow_forwardA solid rubber ball is released from the top of an incline of height h that makes an angle e with the horizontal. (a) If the ball rolls without slipping, what is its speed when it reaches the bottom of the incline? (Use any variable or symbol stated above along with the following as necessary: g for the acceleration of gravity.) Vf = (b) If the ball instead slides without rolling and without friction, what is its speed when it reaches the bottom of the incline? (Use any variable or symbol stated above along with the following as necessary: g for the acceleration of gravity.) V₁ = (c) Compare the time intervals required to reach the bottom in cases (a) and (b). t Frolling tslidingarrow_forwardA cat propels a ball on a horizontal circular track of a 15 cm radius at an initial speed of 2m/s. The ball makes 4 turns before stopping. Part 1:(a) With respect to a tangential axis x whose positive direction is oriented in the direction of motion, what is its tangential acceleration? (b) What is the modulus of the resultant acceleration of the ball as it completes its third turn? Part 2:Find;c) angular acceleration (pay attention to sign conventions!): d) The number of additionnal revolutions the disc will make before stopping: Then replace the following values in your models to test them: Initial angular velocity of the disk: w0=25.6 rad/s The angular speed of the disc after 12 revolutions: w=5.1 rad/sarrow_forward
- A ball slides up a frictionless ramp. It is then rolled without slipping and with the same initial velocity up another frictionless ramp (with the same slope angle). In which case does it reach a greater height, and why?arrow_forwardA 45kg Box is at rest on a 2 meter long board. That end of the board is slowly raised at an incline until the box starts sliding. This point is at 34 degrees, held constant. Given that the kinetic friction is 0.50 N. Please help me solve how long will the box take to reach the bottom of the board?arrow_forwardJohn is pushing his daughter Rachel in a wheelbarrow when it is stopped by a brick 8.00 cm high (see the figure below). The handles make an angle of 0 = 15.5° with the ground. Due to the weight of Rachel and the wheelbarrow, a downward force of 382 N is exerted at the center of the wheel, which has a radius of 15.0 cm. Assume the brick remains fixed and does not slide along the ground. Also assume the force applied by John is directed exactly toward the center of the wheel. (Choose the positive x-axis to be pointing to the right.) (a) What force (in N) must John apply along the handles to just start the wheel over the brick? N (b) What is the force (magnitude in kN and direction in degrees clockwise from the -x-axis) that the brick exerts on the wheel just as the wheel begins to lift over the brick? magnitude KN direction clockwise from the -x-axisarrow_forward
- You place a 15.0-m long, 22-kg uniform ladder against a smooth vertical wall with the bottom of the ladder 3.0 m from the wall. There is a lot of slippery mud so naturally you are worried about the ladder slipping. The coefficient of static friction between the floor and the ladder is 0.28. What distance, measured along the ladder from the bottom, can a 60-kg person climb before the ladder starts to slip?arrow_forwardJohn is pushing his daughter Rachel in a wheelbarrow when it is stopped by a brick 8.00 cm high (see the figure below). The handles make an angle of 0 = 20.0° with the ground. Due to the weight of Rachel and the wheelbarrow, a downward force of 407 N is exerted at the center of the wheel, which has a radius of 18.0 cm. Assume the brick remains fixed and does not slide along the ground. Also assume the force applied by John is directed exactly toward the center of the wheel. (Choose the positive x-axis to be pointing to the right.) & (a) What force (in N) must John apply along the handles to just start the wheel over the brick? 1690.53 X Your response differs from the correct answer by more than 10%. Double check your calculations. N (b) What is the force (magnitude in kN and direction in degrees clockwise from the -x-axis) that the brick exerts on the wheel just as the wheel begins to lift over the brick? magnitude KN direction ° clockwise from the -x-axisarrow_forwardA 45.5‑kg box with the dimensions a×b (the width a = 0.6 m and height b = 1.3 m) is standing on a rough horizontal floor (μs = 1.3). A Professor wants to tip the box over, she pushes on the right side of the box with a horizontal force F = 140 N at a distance h = 1.04 m above the floor as shown in the picture below. The other forces acting on the box are the gravity force (applied to the CoM of the box), the static friction force Fs and the normal force N (both applied to the lower right corner of the box, point Q). Calculate the magnitude and direction of the torques produced by the forces acting on the box relative to the lower right corner (point Q). Assume uniform mass distribution. 1. The torque due to the external force, τQ(due to F) = 2. The torque due to the weight of the box, τQ(due to mg) = 3. The torque due to the friction force, τQ(due to Fs) = 4. The torque due to the normal force, τQ(due to N) =arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning