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In Example 4.5, we pushed on two blocks on a table. Suppose three blocks are in contact with one another on a frictionless, horizontal surface as shown in Figure P4.49. A horizontal force
Figure P4.49
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Principles of Physics: A Calculus-Based Text
- You push an object, initially at rest, across a frictionless floor with a constant force for a time interval t, resulting in a final speed of v for the object. You then repeat the experiment, but with a force that is twice as large. What time interval is now required to reach the same final speed v? (a) 4 t (b) 2 t (c) t (d) t/2 (e) t/4arrow_forwardAn object of mass M is held in place by an applied force F and a pulley system as shown in Figure P4.43. The pulleys are massless and frictionless. (a) Draw diagrams showing the forces on each pulley. Find (b) the tension in each section of rope, T1, T2, T3, T4, and T5 and (c) the magnitude of F. Figure P4.43 44. Any device that allows you to increase the force you exert is a kind of machine. Some machines, such as the prybar or the inclined plane, are very simple. Some machines do not even look like machines. For example, your car is stuck in the mud and you cant pull hard enough to get it out. You do, however, have a long cable that you connect taut between your front bumper and the trunk of a stout tree. You now pull sideways on the cable at its midpoint, exerting a force f. Each half of the cable is displaced through a small angle from the straight line between the ends of the cable. (a) Deduce an expression for the force acting on the car. (b) Evaluate the cable tension for the case where = 7.00 and f = 100 N.arrow_forwardy Problem 3: The diagram shows the all of the forces acting on a body of mass 2.31 kg. The three forces have magnitudes F₁ = 50.6 N, F2 = 20.8 N, and F3 = 75.8 N, with directions as indicted in the diagram, where 0 = 39.6 degrees and p = 30.1 degrees. The dashed lines are parallel to the x and y axes. At t = 0, the body is moving at a speed of 7.93 m/s in the positive x direction. Part (a) What is the x component of the acceleration in m/s²? ax = || Ę Lª F $ Farrow_forward
- In the figure here, a box of Cheerios (mass mc = 1.70 kg) and a box of Wheaties (mass mw = 2.60 kg) are accelerated across a horizontal surface by a horizontal force applied to the Cheerios box. The magnitude of the frictional force on the Cheerios box is 2.10 N, and the magnitude of the frictional force on the Wheaties box is 4.60 N. If the magnitude of F is 12.7 N, what is the magnitude of the force on the Wheaties box from the Cheerios box? Number i Unitarrow_forwardA disk between vertebrae in the spine is subjected to a shearing force of 625 N. Find its shear deformation, taking it to have a shear modulus of 1.30 x 10° N/m². The disk is equivalent to a solid cylinder 0.550 cm high and 2.50 cm in diameter. Question Credit: OpenStax College Physics shear deformation: marrow_forwardElevator Design. You are designing an elevator for a hospital. The force exerted on a passenger by the floor of the elevator is not to exceed 1.60 times the passenger’s weight. The elevator accelerates upward with constant acceleration for a distance of 3.0 m and then starts to slow down. What is the maximum speed of the elevator?arrow_forward
- A force is applied to an initially stationary block of mass 5.70 kg that sits on a horizontal floor as shown. The 98.9N force is applied at 0 = 38° angle. The coefficients of friction between the floor and the block are Hs = 0.525 and uy = 0.325. What is the acceleration of the block? Use g=9.8 m/s2.arrow_forwardA 71 kg skier speeds down a trail, as shown in the figure. The surface is smooth and inclined at an angle of θ = 26° with the horizontal.(a) Draw a free-body diagram for the skier. (b) Determine the magnitude of the normal force acting on the skier.arrow_forwardA robot pushes a 20-kg giftbox on the horizontal surface as part of the moving job for the holiday season, the force is 27 N to the right as shown. The box does not move. The coefficients of friction between the floor and box are μs = 0.75 and μk = 0.40. What is the magnitude (absolute value) of the friction force on the box, in Newtons? Use g = 10 m/s2.arrow_forward
- MY NOTES ASK YOUR TEACHER You have landed on an alien planet and because you have nothing better to do with your time, you have decided to do a physics experiment with a block. Your experiment is shown above. A 60 kg block on a horizontal surface is attached to a rope. The normal force on the block is 378 N. The block is moving to the right, k = 0.6, & the acceleration of the block is 5.22 m/s² to the right. Determine g (the free fall acceleration on this planet) & the tension in the rope. g = FT =arrow_forwardA rifle shoots a 4.30 g bullet out of its barrel. The bullet has a muzzle velocity of 985 m/s just as it leaves the barrel. Assuming a constant horizontal acceleration over a distance of 43.0 cm starting from rest, with no friction between the bullet and the barrel. What force does the rifle exert on the bullet while it is in the barrel? b. Draw a free-body diagram of the bullet while it is in the barrel. Draw a free-body diagram of the bullet just after it has left the barrel. d. How many g 's of acceleration does the rifle give this bullet? e. For how long a time is the bullet in the barrel? a. с. The figarrow_forwardA 80.0-kg skier starts down a 100-m high, 15.0° slope on regular skis. The coefficients of friction between the ski and snow are us 0.250 and uk = 0.150. What is the magnitude of the net force on the skier, in Newtons? Use g = 10.0 m/s². Your answer needs to have 2 significant figures, including the negative sign in your answer if needed. Do not include the positive sign if the answer is positive. No unit is needed in your answer, it is already given in the question statement.arrow_forward
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningClassical Dynamics of Particles and SystemsPhysicsISBN:9780534408961Author:Stephen T. Thornton, Jerry B. MarionPublisher:Cengage Learning