Question 10 1/1 pts For a physics lab experiment, a student whose mass is m = 70.0 kg places a scale on the floor of an elevator. Next the student steps on the scale and the elevator departs. What is the reading on the scale when the elevator is moving up with a speed of 1.50 m/s and an upward acceleration of 2.00 m/s? 547 N ect! 827 N 771 N 582 N 722 N t Answer Question 6 0/1 pts A block of mass m = 2.2 kg sits at rest in the middle of an incline that makes an angle with the horizontal. The coefficient of static friction between the block and the incline is s = 0.400 and the coefficient of kinetic friction is k = 0.300. The angle can be varied between 0=0 and -45. Initially the angle is =0 (so that the incline is parallel to the ground) and then it is slowly increased until it reaches 0=45. At what angle does the block begin to slide down the incline? 17.46 21.8 23.6 swered The block never slides down the incline. 16.7 Question 7 0/1 pts A cart with a trapezoidal shape, as in the figure, carries a blue box of unknown mass on its slanted, flat surface. The surface makes an angle of 15 with the horizontal. The box is not sliding up or down relative to the slanted surface, staying always at the same height. The free-body diagram for the blue box is shown on the right of the figure. 7 is the normal force, and FG is gravity. There are no other forces acting on the blue box. What is the acceleration of the cart? If needed, use g = 9.81 m/s. t Answer swered 9.48 m/s 2.63 m/s 0 m/s 2.54 m/s 4.90 m/s 15 1 ered swer Question 8 0/1 pts A 0.5 kg basketball sits motionless inside a V-shaped wedge. The walls of the wedge make an angle of 36, as shown in the figure. What is the magnitude of the force that the left side of the wedge exerts on the basketball? 4.2 N 2.6 N 7.9 N 3.0 N 2.5 N 36 ered Question 9 0/1 pts A box of mass m = 5.0 kg hangs motionless from a system of strings. The masses of the strings can be neglected compared to the mass of the box. The tension in the horizontal string 2, which is fastened to the vertical wall, is one- half the tension in string 1, which makes an angle to the horizontal and is fastened to the top horizontal wall. What is the tension in string 1? If needed, use g = 9.81 m/s. 1 2 Not enough information 16.4 N 98.1 N swer 56.6 N 5.0 kg