Concept explainers
DATA For the Texas Department of Public Safety, you are investigating an accident that occurred early on a foggy morning in a remote section of the Texas Panhandle. A 2012 Prius traveling due north collided in a highway intersection with a 2013 Dodge Durango that was traveling due east. After the collision, the wreckage of the two vehicles was locked together and skidded across the level ground until it struck a tree. You measure that the tree is 35 ft from the point of impact. The line from the point of impact to the tree is in a direction 39° north of east. From experience, you estimate that the coefficient of kinetic friction between the ground and the wreckage is 0.45. Shortly before the collision, a highway patrolman with a radar gun measured the speed of the Prius to be 50 mph and, according to a witness, the Prius driver made no attempt to slow down. Four people with a total weight of 460 lb were in the Durango. The only person in the Prius was the 150-lb driver. The Durango with its passengers had a weight of 6500 lb, and the Prius with its driver had a weight of 3042 lb. (a) What was the Durango’s speed just before the collision? (b) How fast was the wreckage traveling just before it struck the tree?
Want to see the full answer?
Check out a sample textbook solutionChapter 8 Solutions
University Physics with Modern Physics (14th Edition)
Additional Science Textbook Solutions
Essential University Physics: Volume 1 (3rd Edition)
College Physics: A Strategic Approach (3rd Edition)
Physics for Scientists and Engineers with Modern Physics
The Cosmic Perspective (8th Edition)
Cosmic Perspective Fundamentals
Conceptual Physics (12th Edition)
- A truck (M = 2500kg) collides with a car (m = 1000kg) at a 4-way intersection. Fortunately nobody gets hurt. Suppose the car is going north at 20m/s ( about 45mph) and the truck is coming from the east at 10m/s ( about 22mph). The car and truck stick together after the %3D collision. (a) Find the speed and direction of the car and truck immediately after the collision. (b) Approximately how much energy went into the deformation of the metal that caused the two vehicles to stick together? (c) What assumptions did you make? Thearrow_forwardA child with mass of 16.5 kg stands on the edge of a park bench and leaps into the air. Her initial speed is 2.4 m/s directed at an angle of 30 degrees above the horizontal. After 0.28 seconds what is the horizontal component of her velocity in m/s?arrow_forwardA person driving on I-82 glanced at his phone to read a very important text message. When he looked back up at the road, he saw that the traffic ahead had come to a standstill and he immediately slammed on his brakes. His car created 96.5 m long skid marks before rear-ending another car. Unfortunately, a passenger in the rear-ended car was seriously injured, thus requiring an investigation by the State Patrol. The State Patrol has no proof of distracted driving, however they want to determine if a citation for speeding should be issued. A State Patrol investigator used a 3.9 kg drag sled to determine the coefficient of kinetic friction between the road and the tires of the car. The drag sled's spring scale read 28 N when it was pulled along the ground at a constant speed. Use Newton's Second Law and kinematics to estimate the minimum value of the car's speed when the driver locked the brakes. (answer: about 83 mi/hr) Note: You do not need the mass of the car to answer this question.…arrow_forward
- A person driving on I-82 glanced at his phone to read a very important text message. When he looked back up at the road, he saw that the traffic ahead had come to a standstill and he immediately slammed on his brakes. His car created 96.5 m long skid marks before rear-ending another car. Unfortunately, a passenger in the rear-ended car was seriously injured, thus requiring an investigation by the State Patrol. The State Patrol has no proof of distracted driving, however they want to determine if a citation for speeding should be issued. A State Patrol investigator used a 3.9 kg drag sled to determine the coefficient of kinetic friction between the road and the tires of the car. The drag sled’s spring scale read 28 N when it was pulled along the ground at a constant speed. Use Newton’s Second Law and kinematics to estimate the minimum value of the car’s speed when the driver locked the brakes. (answer: about 83 mi/hr) Note: You do not need the mass of the car to answer this…arrow_forwardAn investigation of an automobile crash suggests that vehicle A was moving at 52 mph toward the south and vehicle B was moving at an unknown speed toward the north, when the two cars collided, sticking together after the collision. Vehicle A weighs 1350 lbs., and vehicle B weighs 1893 lbs. If the cars did not move significantly after their collision, find the initial speed of vehicle B in mph. Answer: mph (miles per hour)arrow_forwardYou step onto a hot beach with your bare feet. A nerve impulse, generated in your foot, travels through your nervous system at an average speed of 110 m/s. How much time does it take for the impulse, which travels a distance of 1.8 m, to reach your brain?arrow_forward
- A red train traveling at 72 km/h and a green train traveling at 144 km/h are headed toward each other along a straight, level track.When they are 950 m apart, each engineer sees the other’s train and applies the brakes.The brakes slow each train at the rate of 1.0 m/s2. Is there a collision? If so, answer yes and give the speed of the red train and the speed of the green train at impact, respectively. If not, answer no and give the separation between the trains when they stoparrow_forwardA car of mass 6000 kg moving at 40 m/s is suddenly brought to a stop when a deer crosses the road. If a braking force of 600,000 N/m is needed to bring the car to a stop, what was the duration of the force?arrow_forwardDuring a head on collision, the passengers in the front seat of a car accelerate from 13.3m/s to rest in 0.10s. The driver of the car held out their arm to stop their 25kg child from smashing into the dashboard. What force in pounds (1N = 0.225lbs) is needed to keep the child from moving?arrow_forward
- A red train traveling at 72 miles/hour (mph) and a green train traveling at 100 mph are headed toward one another along a straight, level track. When they are 2500 feet apart, each engineer sees the other's train and applies the brakes. The brakes decelerates each train at the rate of 2.0 meters per second squared. Is their a collision? If so, what is the speed of each train at impact? If not, what is the separation between the trains when they stop? (Non-ro...arrow_forwardA red train traveling at 72 miles/hour (mph) and a green train traveling at 100 mph are headed toward one another along a straight, level track. When they are 2500 feet apart, each engineer sees the other's train and applies the brakes. The brakes decelerates each train at the rate of 2.0 meters per second squared. Is their a collision? If so, what is the speed of each train at impact? If not, what is the separation between the trains when they stop? Give the given and solution:arrow_forwardA 100 kg football player is traveling at 11 m/s when he is stopped in 0.1 seconds. What was the magnitude of the force that stopped the player?arrow_forward
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningGlencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-Hill