Experimental tests have shown that bone will rupture if it is subjected to a force density of 1.03 x 10® N/m². Suppose a 70.0-kg person carelessly rollerskates into an overhead metal beam that hits his forehead and completely stops his forward motion. If the area of contact with the person's forehead is 1.5 cm², what is the greatest speed with which he can hit the wall without breaking any bone if his head is in contact with the beam for 10.0 ms?

Experimental tests have shown that bone will rupture if it is subjected to a force density of 1.03 x 10® N/m². Suppose a 70.0-kg person carelessly rollerskates into an overhead metal beam that hits his forehead and completely stops his forward motion. If the area of contact with the person's forehead is 1.5 cm², what is the greatest speed with which he can hit the wall without breaking any bone if his head is in contact with the beam for 10.0 ms?

Physics for Scientists and Engineers, Technology Update (No access codes included)

9th Edition

ISBN:9781305116399

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter15: Oscillatory Motion

Section: Chapter Questions

Problem 15.83AP: Two identical steel balls, each of mass 67.4 g, are moving in opposite directions at 5.00 m/s. They...

See similar textbooks

Similar questions

You are part of a team in an engineering class that is working on a scale model of a new design for a life vest. You have been asked to find the mass of a piece of foam that will be used for flotation. Because the piece is too bulky to fit on your balance, you break it into two parts. You measure the mass of the first part as 128.3 0.3 g and the second part as 77.0 0.3 g. a. What are the maximum and minimum values for the total mass you might reasonably report? b. What is the best estimate for the total mass of the foam? Hint: Propagation of uncertainty is described in Appendix A.
Two identical steel balls, each of mass 67.4 g, are moving in opposite directions at 5.00 m/s. They collide head-on and bounce apart elastically. By squeezing one of the balls in a vise while precise measurements are made of the resulting amount of compression, you find that Hookes law is a good model of the balls elastic behavior. A force of 16.0 kN exerted by each jaw of the vise reduces the diameter by 0.200 mm. Model the motion of each ball, while the balls are in contact, as one-half of a cycle of simple harmonic motion. Compute the time interval for which the balls are in contact. (If yon solved Problem 57 in Chapter 7, compare your results from this problem with your results from that one.)
A man claims that he can hold onto a 12.0-kg child in a head-on collision as long as he has his seat belt on. Consider this man in a collision in which he is in one of two identical cars each traveling toward the other at 60.0 mi/h relative to the ground. The car in which he rides is brought to rest in 0.10 s. (a) Find the magnitude of the average force needed to hold onto the child. (b) Based on your result to part (a), is the mans claim valid? (c) What does the answer to this problem say about laws requiring the use of proper safety devices such as seat belts and special toddler seats?
Why is it preferable for airplanes to take off into the wind rather than with the wind?
A 5.0-g bullet leaves the muzzle of a rifle with a speed of 320 m/s. What force (assumed constant) is exerted on the bullet while it is traveling down the 0.82-m-long barrel of the rifle?
Boxing gloves are padded to lessen the force of a blow. (a) Calculate the force exerted by a boxing glove on an opponent's face, if the glove and face compress 7.50 cm during a blow in which the 7.00-kg arm and glove are brought to rest from an initial speed of 10.0 m/s. (b) Calculate the force exerted by an identical blow in the gory old days when no gloves were used and the knuckles and face would compress only 2.00 cm. (c) Discuss the magnitude of the force with glove on. Does it seem high enough to cause damage even though it is lower than the force with no glove?
Bruce Lee was famous for breaking concrete blocks with a single karate chop. From slow-motion video, the speed of his 1.50-kg hand descending on a block was estimated to be 15.0 m/s, which decreased to a speed of 0.500 m/s in the 2.50 103 s during which his hand made contact with and broke through the block. The maximum shear stress a concrete block can be subjected to before breaking is 9.50 105 N/m2. a. What was the force exerted by Lees hand on the block? b. If a typical concrete block broken by Lee was 3.00 cm thick and 15.2 cm wide, what is the shear stress experienced by the concrete block? c. Will the concrete block succumb to Lees karate chop?
A bullet is accelerated down the barrel of a gun by hot gases produced in the combustion of gun powder. What is the average force exerted on a 0.0300-kg bullet to accelerate it to a speed of 600 m/s in a time of 2.00 ms (milliseconds)?
1.A 1500-N force is required to raise an aluminum slab (the density of aluminum is 2700 kg/m3 ) to a surface of an ocean. The force required to lift it out of the water is approximately 2.A 6-kg stone moving north at 3 m/s collides with a 4-kg lump of clay moving west at 2 m/s. The stone becomes embedded in the clay. What is the speed of the composite body after the collision? 3.A barge is 5 m wide and 7 m long. When a bulldozer pulls onto the barge, it sinks 3 cm lower in the sea water. What is the weight of the bulldozer? 4.The object shown rotates about an axis perpendicular to the paper and through point P. The kinetic energy of the object is equal to 5.6 J. If M = 1.5 kg and L = 0.75 m, what is the angular velocity of the object? Neglect the mass of the connecting rods and treat the masses as particles. 5.What would a person who weighs 700 N on the earth weigh on a planet whose mass and radius were both 1/3 those of the earth? 6.A 3-kg particle moves in the xy plane with a…
A kids rocket team launches one smaller rocket through a guide tube 1.7 m long. The rocket has a mass of 450 g and the exhaust pressure in the tube provides a constant net force of 265 N. I already answered part (a) I just need help with part (b) A. How fast will the rocket be moving when it exits the tube? 44.5 m/s answer The kids rocket team now launches the rocket from a baseball outfield so in lands ontop of a new parking structure, 15 m above launch point and 32 m (horizontally) from the launch point. Unfortunately, tilting the launch tube greatly increases the friction, slowing the rocket. B. What is the minimum launch speed (neglecting air resistance) so that the rocket will just barely make it to the edge of the roof?
Problem 1: The puffer fish (tetradontiade) can employ a defense mechanism whereby it fills its stomach with water until the fish is almost spherical in shape. The shape, in conjunction with its external spines, are a significant deterrent to predators. Suppose that a puffer fish takes in water until its mass has increased by f = 1.52 times its initial mass. In this state, and initially at rest, the puffer fish expels the water with a speed s in one direction, while the fish recoils in the opposite direction at a speed v. For this problem neglect the drag-force effects of the surrounding ocean water. Part (a) Write an expression for v/s in terms of f. Part (b) What is the numerical value of your answer to part (a)?
A kids rocket team launches one smaller rocket through a guide tube 1.7 m long. The rocket has a mass of 450 g and the exhaust pressure in the tube provides a constant net force of 265 N. A. How fast will the rocket be moving when it exits the tube?