A small block with mass 0.0500 kg slides in a vertical circle of radius 0.475 m on the inside of a circular track. During one of the revolutions of the block, when the block is at the bottom of its path, point A, the magnitude of the normal force exerted on the block by the track has magnitude 3.80 N . In this same revolution, when the block reaches the top of its path, point B, the magnitude of the normal force exerted on the block has magnitude 0.665 N . How much work was done on the block by friction during the motion of the block from point A to point B?

Multiple-Concept Example 5 reviews many of the concepts that play a role in this problem. An extreme skier, starting from rest, coasts down a mountain that makes an angle of 32.5° with the horizontal. The coefficient of kinetic friction between her skis and the snow is 0.244. She coasts for a distance of 12.3 m before coming to the edge of a cliff. Without slowing down, she skis off the cliff and lands downhill at a point whose vertical distance is 3.67 m below the edge. How fast is she going just before she lands? Number i eTextbook and Media Save for Later Units Attempts: 0 of 5 used Submit Answer

A mysterious force acts on all particles along a particular line and always points towards a particular point P on the line. The magnitude of the force on a particle increases as the cube of the distance from that point, that is, F∝ r3, if the distance from the P to the position of the particle is r. It has been determined that the constant of proportionality is 0.23 N/m3, i.e. the magnitude of the force on a particle can be written as 0.23r3, when the particle is at a distance r from the force center. Find the magnitude of the potential energy, in joules, of a particle subjected to this force when the particle is at a distance 0.21 m from point P assuming the potential energy to be zero when the particle is at P.  PE= ?

A light plane of mass 1000kg makes an emergency landing on a short runway. With its engine off, it lands on the runway at a speed of 40m⋅s-1 . A hook on the plane snags a cable attached to a 120kg sandbag and drags the sandbag along. If the coefficient of friction between the sandbag and the runway is µk = 0.4, and if the plane’s brakes give an additional retarding force of magnitude 1400N, how far does the plane go before it comes to a stop?

Under the influence of its drive force, a snowmobile is moving at a constant velocity along a horizontal patch of snow. When the drive force is shut off, the snowmobile coasts to a halt. The snowmobile and its rider have a mass of 139 kg. Under the influence of a drive force of 180 N, it is moving at a constant velocity whose magnitude is 5.43 m/s. The drive force is then shut off. Find (a) the distance in which the snowmobile coasts to a halt and (b) the time required to do so. (a) S = (b) t = i i

The car is fully loaded with passengers and has a total mass of 575 kg. At point A, the car is at the lowest point in a circular arc of radius  r1 = 12.4 m.  At point B, the car is at the highest point of a circular arc of radius  r2 = 17.3 m.   (a) If the car has a speed of 25.0 m/s at point A, what is the magnitude of the force (in N) of the track on the car at this point?   (b) What is the maximum speed (in m/s) the car can have at point B in order for the car to maintain contact with the track at all times (that is, so that it does not "jump" off the track)?

A 19.0 kg box is placed at the top of an inclined plane and released to either move freely or sit at rest. The plane is at an angle of 30° above the ground and has a total length of d = 2.80 m along the incline. The coefficient of static friction between the box and the plane is us = 0.40 and the coefficient of kinetic friction is pk = 0.30. What kind of friction does the box experience once it is released, and what is its magnitude? m d Kinetic, Fkf - 55.9 N Static, Fsf = 74.5 N Static, Fsf = 64.5 N Kinetic, Fkf = 48.4 N

Problem 8: A car of mass m = 1020 kg is traveling down a 0 = 12 degree incline. When the car's speed is vo = 11 m/s, a mechanical failure causes all four of its brakes to lock. The y coefficient of kinetic friction between the tires and road is u = 0.45.

A woman at an airport is rolling her suitcase (mass = 20 kg) at an initial velocity of 1 m/s by pulling on a strap at an angle of 30° above the horizontal with a force of 33 N. The woman starts to speed up when she realizes that she is late for her flight. She pulls the suitcase over a distance of 50 m as she walks to her gate. What is the speed of the suitcase when she reaches her gate? (You can neglect friction in this problem. Give your answer in m/s.)

Under the influence of its drive force, a snowmobile is moving at a constant velocity along a horizontal patch of snow. When the drive force is shut off, the snowmobile coasts to a halt. The snowmobile and its rider have a mass of 143 kg. Under the influence of a drive force of 220 N, it is moving at a constant velocity whose magnitude is 4.38 m/s. The drive force is then shut off. Find (a) the distance in which the snowmobile coasts to a halt and (b) the time required to do so. (a) s= (b) t = i i + +