Item 13 Part A < 13 of 33 Review | Constants Dancers experience large forces associated with the jumps they make. For example, when a dancer lands after a vertical jump, the force exerted on the head by the neck must exceed the head's weight by enough to cause the head to slow down and come to rest. The head is about 9.4% of a typical person's mass. Video analysis of a 65-kg dancer landing after a vertical jump shows that her head decelerates from 4.0 m/s to rest in a time of 0.20 s. While the dancer is in the air and holding a fixed pose, what is the magnitude of the force her neck exerts on her head? ON 60 N 120 N 180 N Submit Request Answer Item 14 In treating spinal injuries, it is often necessary to provide some tension along the spinal column to stretch the backbone. One device for doing this is the Stryker frame, illustrated in part (a) of the figure. A weight W is attached to the patient (sometimes around a neck collar, as shown in part (b) of the figure), and friction between the person's body and the bed prevents sliding.( Figure 1) Figure 1 of 1 (a) (b) Part A 14 of 33 Review | Constants If the coefficient of static friction between a 69.5 kg patient's body and the bed is 0.795, what is the maximum traction force along the spinal column that W can provide without causing the patient to slide? Express your answer in newtons. ? T= Submit Request Answer N Part B Under the conditions of maximum traction, what is the tension in each cable attached to the neck collar? Express your answer in newtons. T = ? N Submit Request Answer Item 16 Part A You have landed on an unknown planet, Newtonia, and want to know what objects weigh there. When you push a certain tool, starting from rest, on a frictionless horizontal surface with a 14.0 N force, the tool moves 17.0 m in the first 2.50 s. You next observe that if you release this tool from rest at 11.0 m above the ground, it takes 2.58 s to reach the ground. What does the tool weigh on Newtonia? Express your answer with the appropriate units. ? WN = Value Units Submit Request Answer ( > 16 of 33 > Review | Constants Part B What does it weigh on earth? Express your answer in newtons. WE = Value Submit Request Answer ? Units