An object of mass m = 5.00 kg, attached to a spring scale, rests on a frictionless, horizontal surface as shown in Figure. The spring scale, attached to the front end of a boxcar, reads zero when the car is at rest. (a) Determine the acceleration of the car if the spring scale has a constant reading of 18.0 N when the car is in motion. (b) What constant reading will the spring scale show if the car moves with constant velocity? Describe the forces on the object as observed (c) by someone in the car and (d) by someone at rest outside the car.

Two blocks are positioned on surfaces, each inclined at the same angle of 55.7 degrees with respect to the horizontal. The blocks are connected by a rope which rests on a frictionless pulley at the top of the inclines as shown, so the blocks can slide together. The mass of the black block is 2.73 kg, and this time there is NO friction. What is must be the mass of the white block if both blocks are to slide to the LEFT at an acceleration of 1.5 m/s^2? a. 2.65 kg b. 3.97 kg c. 1.23 kg d. 5.96 kg

Two blocks are positioned on surfaces, each inclined at the same angle of 42.7 degrees with respect to the horizontal. The blocks are connected by a rope which rests on a frictionless pulley at the top of the inclines as shown, so the blocks can slide together. The mass of the black block is 4.44 kg, and this time there is NO friction. What is must be the mass of the white block if both blocks are to slide to the LEFT at an acceleration of 1.5 m/s^2?     7.03 kg     2.94 kg     10.55 kg     4.69 kg

A 1,200-kg car is pulling a 315-kg trailer. Together, the car and trailer have an acceleration of 2.10 m/s? in the positive x-direction. Neglecting frictional forces on the trailer, determine the following. (Indicate the direction with the sign of your answer. Assume forward motion is along the positive x-axis and upwards is along the positive y-axis. Assume the trailer's weight is entirely supported by it's own tires.) (a) the net force on the car (in the x-direction) (b) the net force on the trailer (in the x-direction) N (c) the magnitude and direction of the force exerted by the trailer on the car magnitude direction Select-v (d) the resultant force exerted by the car on the road magnitude N direction * (below the horizontal and rearward)

A robot pushes a 20-kg box on the horizontal surface as part of the moving job. The force is 35 N to the left shown, and the box does not move. The coefficients of friction between the floor and box are µs = 0.75 and uk = 0.40. What is the minimum pushing force (magnitude only) needed to move the box, in Newtons? Useg = 10 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.

A woman stands on a scale while riding in an elevator. When the elevator is at rest, the scale reads 60kg. What will be the reading of the scale in kg when the elevator accelerates. (a) upward at 1.2 m/s^2. (b) downward at 1.2 m/s^2. (c) At what acceleration of the elevator would the person appear to be weightless? Draw the FBD of the problem.

An elevator filled with passengers has a mass of 1.70 × 103 kg . (a) The elevator accelerates upward from rest at a rate of 1.20 m/s2 for 1.50 s. Calculate the tension in the cable supporting the elevator. (b) The elevator continues upward at constant velocity for 8.50 s. What is the tension in the cable during this time? (c) The elevator decelerates at a rate of 0.600 m/s2 for 3.00 s. What is the tension in the cable during deceleration? (d) How high has the elevator moved above its original starting point, and what is its final velocity?