john smith
New member
1. Alanzo, running at a constant 3 m/s, is the first to reach you. You stagger to your feet as he approaches, but before you can speak even the first word of your explanation, Alanzo tackles you in a perfectly inelastic collision. If you were stationary when hit and have a mass of 70 kg, what is the kinetic energy (in J) of you and Alanzo together after the collision? You may consider the collision takes place in 1-D, that you and Alanzo form an isolated system, and that Alazno’s mass is 80 kg.
2. You quickly recover from the tackle and shove Alanzo aside. By now Zacarias has arrived on the scene and you greet him warmly by completely burying the 15 cm blade of your Fällkniven F1 hunting knife in his chest. If you perform 300 J of work in the process and the blade enters normal to the surface of his chest, what is the magnitude of the average resistive force (in N) that Zacarias’s chest exerts on your knife?
3. You quickly grab the bourbon bottle from the table, spin around, and smash it across Alanzo’s face, just as he was preparing to hit you again. He staggers away, disoriented, but finally pulls himself together about 5 m from you. During this time you have retrieved your knife from the lifeless Zacarias and have thrown it with a speed of 20 m/s directly at Alanzo. The impact of the knife on his neck causes Alanzo’s to stagger backward and subsequently fall through a window and down to the alley below. During his fall, Alanzo is subject to a constant force of wind resistance of 100 N. If he hits the ground with a speed of 11 m/s, how high (in m) is the window from the ground? Alanzo’s mass is 80 kg and his initial vertical speed when he fell through the window is zero.
4. As a courtesy to the owner of the Grasshopper, you drag the lifeless, but very bloody, 80 kg body of Zacarias 10 m to the outside of the bar. The force you apply to pull the body is at a 60° angle to the floor. What is the work (in J) done by this pulling force if you drag the body at constant velocity? The coefficient of kinetic friction between the body and the floor is 0.2.
5. What is the power (in W) exerted by your pulling force if you pull the body 10 m in 50 seconds?
6. What is the power (in W) exerted by the force of kinetic friction acting on the body as you pull it for 10 m in 50 seconds?
2. You quickly recover from the tackle and shove Alanzo aside. By now Zacarias has arrived on the scene and you greet him warmly by completely burying the 15 cm blade of your Fällkniven F1 hunting knife in his chest. If you perform 300 J of work in the process and the blade enters normal to the surface of his chest, what is the magnitude of the average resistive force (in N) that Zacarias’s chest exerts on your knife?
3. You quickly grab the bourbon bottle from the table, spin around, and smash it across Alanzo’s face, just as he was preparing to hit you again. He staggers away, disoriented, but finally pulls himself together about 5 m from you. During this time you have retrieved your knife from the lifeless Zacarias and have thrown it with a speed of 20 m/s directly at Alanzo. The impact of the knife on his neck causes Alanzo’s to stagger backward and subsequently fall through a window and down to the alley below. During his fall, Alanzo is subject to a constant force of wind resistance of 100 N. If he hits the ground with a speed of 11 m/s, how high (in m) is the window from the ground? Alanzo’s mass is 80 kg and his initial vertical speed when he fell through the window is zero.
4. As a courtesy to the owner of the Grasshopper, you drag the lifeless, but very bloody, 80 kg body of Zacarias 10 m to the outside of the bar. The force you apply to pull the body is at a 60° angle to the floor. What is the work (in J) done by this pulling force if you drag the body at constant velocity? The coefficient of kinetic friction between the body and the floor is 0.2.
5. What is the power (in W) exerted by your pulling force if you pull the body 10 m in 50 seconds?
6. What is the power (in W) exerted by the force of kinetic friction acting on the body as you pull it for 10 m in 50 seconds?