3. [-/3 Points] DETAILS In the system shown in the figure below, a horizontal force acts on an object of mass m = 5.50 kg. The horizontal surface is frictionless. Consider the acceleration of the sliding object as a function of FX. mi m2 F N (a) For what values of FX (in N) does the object of mass m Fx > = 4.50 kg accelerate upward? (Indicate the direction of the force with the sign of your answer. Let the positive x-direction be to the right.) (b) For what values of FX (in N) is the tension in the cord zero? (Indicate the direction of the force with the sign of your answer. Let the positive x-direction be to the right.) Fx N (c) Plot the acceleration of the m2 object versus F. Include values of F from -100 N to +100 N. -100 -50 a (m/s) Fx (N) 50 100 -100 -50 a (m/s) Fx (N) 50 100 -50 a (m/s) 5 50 Fx (N) 100 -100 -50 a (m/s) 5 Fx (N) 50 100 ju njoj mja -10 -15 -20 -10 -15 -20 + -10 -15 -20 -10 -15 -20 Submit Answer 4. [-/2 Points] DETAILS A 26.0-kg block is initially at rest on a horizontal surface. A horizontal force of 72.0 N is required to set the block in motion, after which a horizontal force of 61.0 N is required to keep the block moving with constant speed. (a) Find the coefficient of static friction between the block and the surface. (b) Find the coefficient of kinetic friction between the block and the surface. Submit Answer 5. [-/1 Points] DETAILS A 8.00-kg hanging object is connected by a light, inextensible cord over a light, frictionless pulley to a 5.00-kg block that is sliding on a flat table. Taking the coefficient of kinetic friction as 0.190, find the tension in the string. (The block slides to the right in the diagram below.) N m Submit Answer Mo 6. [-/2 Points] DETAILS A car accelerates down a hill (see figure below), going from rest to 22.0 m/s in 4.60 s. A toy inside the car hangs by a string from the car's ceiling. The ball in the figure represents the toy, of mass 0.600 kg. The acceleration is such that the string remains perpendicular to the ceiling. (a) Determine the angle 0. (b) Determine the tension in the string. N Submit Answer 7. [-/5 Points] DETAILS A 2.90-kg block starts from rest at the top of a 30.0 incline and slides a distance of 2.10 m down the incline in 1.80 s. (a) Find the magnitude of the acceleration of the block. m/s (b) Find the coefficient of kinetic friction between block and plane. (c) Find the friction force acting on the block. magnitude direction ---Select--- N (d) Find the speed of the block after it has slid 2.10 m. m/s Submit Answer