Problems Lecture 05 PDF

Problems Lecture 05 Further application of Newton’s laws: Friction and Drag You want to move a 51 kg crate across a level floor. To start the crate moving, you have to pull with a 230 N horizontal force. (a) What is the coefficient of static friction? You want to move a 51 kg crate across a level...

Problems Lecture 05 Further application of Newton’s laws: Friction and Drag You want to move a 51 kg crate across a level floor. To start the crate moving, you have to pull with a 230 N horizontal force. (a) What is the coefficient of static friction? You want to move a 51 kg crate across a level floor. Once the crate starts to move, you can keep it moving at constant velocity with only 200 N. (b) What is the coefficient of kinetic friction? You want to move a 51 kg crate across a level floor. To start the crate moving, you have to pull with a 230 N horizontal force. (c) What is the friction force if the crate is at rest on the surface and a horizontal force of 50 N is applied to the box? You move a 51 kg crate across a level floor by pulling upward on the rope at an angle of 30° above the horizontal. How hard must you pull to keep it moving with constant velocity? The coefficient of kinetic friction between the floor and the create is 0.40. A flatbed truck slowly tilts its bed upward to dispose a 95.0 kg crate. For small angles of tilt the create stays put, but when the tilt angle exceeds 23.3°, the crate begins to slide. What is the coefficient of static friction between the bed of the truck and the crate? Continue……!! Once the create begins to slide, it accelerates. Find its acceleration. The till angle at which it begins to slide is 23.3°, and the coefficient of kinetic friction is 0.40 A toboggan loaded with students (total mass 𝑚) slides down a snow-covered hill that slopes at a constant angle 𝛼. The toboggan is well-waxed, so there is virtually no friction. What is the normal force and the acceleration of the students? A toboggan loaded with students (total mass 𝑚) slides down a snow-covered hill that slopes at a constant angle 𝛼. The wax has worn off, so there is now a nonzero coefficient of kinetic friction 𝜇𝑘. The slope has just the right angle to make the toboggan slide with constant velocity. Find this angle in terms of 𝑚, 𝜇𝑘 , and 𝛼? A toboggan loaded with students (total mass 𝑚) slides down a snow-covered hill that slopes at a constant angle 𝛼. The wax has worn off, so there is now a nonzero coefficient of kinetic friction 𝜇𝑘. Derive an expression for the acceleration in terms of 𝑚, 𝜇𝑘 , and 𝛼? A block with mass m1 = 4.00 𝑘𝑔 and a ball with mass m2 = 7.00 𝑘𝑔 are connected by a light string that passes over a massless, frictionless pulley. Find the acceleration of the two objects and the tension in the string if the coefficient of kinetic friction of the table and the block is 0.40. A 2 kg block is pushed against a spring, as shown in the picture. The spring is attached to the wall and has a force constant of 500 N/m. If the coefficient of static friction between the box and the floor is 0.8, find the maximum distance in which the box can compress the spring and not move after it is released. A 75 kg skydiver and his 0.020 kg pet mouse falling after jumping from a plane are shown in the figure. Find the terminal speed of each. Use the Drag Coefficient for cylinder 1.1, and the density of air 1.2 kg/m3.