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The normal pressure acting on the disk of the sander is given by
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Chapter 7 Solutions
International Edition---engineering Mechanics: Statics, 4th Edition
- The 104-lb force Pis applied to the 220-lb crate, which is stationary before the force is applied. Determine the magnitude and direction of the friction force Fexerted by the horizontal surface on the crate. The friction force is positive if to the right, negative if to the left. Assume 4, = 0.47, Hz = 0.38. Answer: F = Ibarrow_forwardThis is an example diagram of Atwood’s Machine. This machine works by hanging two masses on a pulley, with each mass being acted upon by gravity. Since the masses are on opposite sides of the pulley, their weights oppose each other, and the net acceleration is less than g. To see this, please draw in all of the relevant forces in the diagram below. Be sure to indicate which direction friction in the pulley is acting. Assume m1 > m2.arrow_forward2. The 100 – Ib force acts as shown on a 300 - Ib block placed on an inclined plane. The coefficients of friction between the block and the plane are us = 0.25 and Hk = 0.20. Determine whether the block is in equilibrium, and find the value of the friction for the friction force. 300 Ib 100 lbarrow_forward
- An object with weight W is dragged along a horizontal plane by a force acting along a horizontal plane by a force acting along a rope attached to the object. If the rope makes an angle 0 with the plane, then the magnitude of the force is µW F = µ sin 0 + cos 0 where u is the coefficient of friction a. Find the rate of change of F wrt 0. b. The value of 0 at maximum or minimum value of F.arrow_forwardP (N) * 2. The force P is applied to the block m kg, which is stationary before the force is applied. Determine the magnitude and direction of the friction force f exerted by the horizontal surface on the block. m kg 30° H = 0.80 H = 0.60 %3D Figure 2. 25 kg m = .... ..... .... .. P = 245.25 newton ....... ..... .......arrow_forwardIf there is n friction in the system, the Lagrange's equation will be based only on kinetic energy and protentional energy only. Select one: O True O False III Oarrow_forward
- For the delivery truck shown: The mass of the truck is 4000 kg. The horizontal distance from the rear tires to the center of mass, G, is L1 = 3 m The vertical distance from the ground to G is d = 3m The horizontal distance from the rear tires to the front tires is L2 = 5 m. d The delivery truck is traveling at 20 m/s when the brakes are applied. The truck skids to a stop, so that the friction force is applied to the tires by the road.* The coefficient dynamic friction is uk = 0.60 *If it did not skid, then the friction force would be between the brake pads and the brake disc, which would be above the road. Calculate the distance that the truck travels before it stops. Use Σ MA = Ia + d x m*a for the following: 'O' Calculate the left side of this equation: Σ MA G L1 → L2 Calculate the right side of this equation: I*α + d x m*a d+ x m*a is from r x m*a (cross product), so, determine the sign by considering the cross product. Set the left and right right sides equal to each other and…arrow_forwardIn an amusement park ride, riders stand against the vertical wall of a spinning cylinder. The floor falls away and the riders are held up by friction. If the radius of the cylinder is R, find the minimum number of revolutions per time necessary if the coefficient of friction between a rider and the wall is given.arrow_forwardThe motorcycle weighs 151 kg and the driver weighs 64 kg. Dimensions: l1 = 0,31 m and l2 = 0,23 m Determine the support force on the rear tire.arrow_forward
- Blocks mị and m2 are connected by a rope as shown in the figure. There is friction between mi and the wall, where the coefficient of static friction is ls. There is no friction between m2 and the ramp. An unknown force P is applied to mį so that mị is about to slip down the wall and m2 is about to move down the ramp. If the magnitude of the normal force on m2 is n2, find m2, the magnitude of P, the magnitude of the friction force on m1, and the magnitude of the tension force in the rope. The knowns are ls, n2, m1, g, and 0. P = ? Hs rope wall no friction m2 = ? ramparrow_forwardQ1: In the Figure 1, two forces (P & Q) are acting on the same fixed point A. Find the resultant of these forces and its angle with the horizon by using: (a) Graphical solution. (b) Trigonometric solution. Q = 60 N Figure 1: P 40 N 35 Q2: A block of 15 kg was place on an inclined surface as shown in Figure 2. If the static coefficient of friction between the block and the surface is 0.3, find: (a) the maximum friction force. (b) the equilibrium state of the block. 15 kg Figure 2: 30arrow_forwardThis climber (mass=52kg) is maintaining this posture while grabbing onto a rock at P3 and reaching for the wall with her right hand (no contact of wall and right hand). The rock at P1 applies a force of 187.4N at an angle of 140.2 deg from the positive x axis on her right foot at P1. The rock at P2 and the climber's pants have a coefficient of static friction of 0.78 and the y component of the force of the rock on her pants is 144.0 N upward. The rocks at P1 and P2 are vertical surfaces. The friction forces acting at P1 and P2 are as large as friction will allow. Analyze the forces in the frontal plane as shown and show mechanical rationale for each question. a) What is the net interaction of the her left hand on the rock at P3? b) Which surface (P1 or P2) has a lower coefficient of static friction? If she took off her shoes and tried to hold this position with her socks (coefficient of static friction of her socks and rock is 0.78), will she be able to maintain static equilibrium? C)…arrow_forward
- International Edition---engineering Mechanics: St...Mechanical EngineeringISBN:9781305501607Author:Andrew Pytel And Jaan KiusalaasPublisher:CENGAGE L