Your forehead can withstand a force of about 6.0 kN before fracturing, while your cheekbone can only withstand about 1.3 kN.
a. If a 140 g baseball strikes your head at 30 m/s and stops in 0.0015 s, what is the magnitude of the ball’s acceleration?
b. What is the magnitude of the force that stops the baseball?
c. What force does the baseball apply to your head? Explain.
d. Are you in danger of a fracture if the ball hits you in the forehead? In the cheek?
Want to see the full answer?
Check out a sample textbook solutionChapter 5 Solutions
Student Workbook for College Physics: A Strategic Approach
Additional Science Textbook Solutions
An Introduction to Thermal Physics
The Cosmic Perspective (8th Edition)
Essential University Physics: Volume 1 (3rd Edition)
Introduction to Electrodynamics
Sears And Zemansky's University Physics With Modern Physics
Life in the Universe (4th Edition)
- (a) A cat with a mass of 850 kg in moving to the right with a constant speed of 1.44 m/s. What is the total force on the cat ? (b) What is the total force on the cat if it is moving to the left?arrow_forwardA ball hanging from a light string or rod can be used as an accelerometer (a device that measures acceleration) as shown in Figure P5.18. What force causes the deflection of the ball? Is the cart in the lower part of the photo an inertial reference frame? How can the balls deflection be used to find the carts acceleration? In which direction is the cart accelerating? Explain your answers.arrow_forward(a) A car with a mass of 850 kg is moving to the right with a constant speed of 1.44 m/s. What is the total force on the car? (b) What is the total force on the car if it is moving to the left?arrow_forward
- A car of mass 875 kg is traveling 30.0 m/s when the driver applies the brakes, which lock the wheels. The car skids for 5.60 s in the positive x-direction before coming to rest. (a) What is the cars acceleration? (b) What magnitude force acted on the car during this time? (c) How far did the car travel?arrow_forwardThe International Space Station has a mass of approximately 370,000 kg. (a) What is the force on a 150-kg suited astronaut if she is 20 m from the center of mass of the station? (b) How accurate do you think your answer would be?arrow_forwardA 5.00105 -kg rocket is accelerating straight up. Its engines produce 1.250107 N of thrust, and air resistance is 4.50106 N. What is the rocket's acceleration? Explicitly show how you follow the steps in the Problem-Solving Strategy for Newton's laws of motion.arrow_forward
- (a) Why does an ordinary rifle recoil (kick backward) when fired? (b) The barrel of a recoilless rifle is open at both ends. Describe how Newton’s third law applies when one is fired. (c) Can you safely stand close behind one when it is fired?arrow_forwardA weight lifter stands on a bathroom scale. He pumps a barbell up and down. What happens to the reading on the scale as he does so? What If? What if he is strong enough to actually throw the barbell upward? How does the reading on the scale vary now?arrow_forwardA brave but inadequate rugby player is being pushed backward by an opposing player who is exerting a force of 800 N on him. The mass of the losing player plus equipment is 90.0 kg, and he is accelerating at 1.20 m/s2 backward. (a) What is the force of friction between the losing player's feet and the grass? (b) What force does the winning player exert on the ground to move forward if his mass plus equipment is 110 kg? (c) Draw a sketch of the situation showing the system of interest used to solve each part. For this situation, draw a free-body diagram and write the net force equation.arrow_forward
- A cosmic ray muon with mass m = 1.88 1028 kg impacting the Earths atmosphere slows down in proportion to the amount of matter it passes through. One such particle, initially traveling at 2.50 108 m/s in a straight line, decreases in speed to 1.50 108 m/s over a distance of 1.20 km. a. What is the magnitude of the force experienced by the muon? b. How does this force compare to the weight of the muon?arrow_forwardIn Figure P1.84, the pulleys and the cord are light, all surfaces are frictionless, and the cord does not stretch. (a) How does the acceleration of block 1 compare with the acceleration of block 2? Explain your reasoning. (b) The mass of block 2 is m2 = 1.30 kg. Derive an expression for the acceleration of the block having mass m2 as a function of the mass of block 1, m1. (c) What does the result of part (b) predict if m1 is very much less than 1.30 kg? (d) What does the result of part (b) predict if m1 approaches infinity? (e) In this last case, what is the tension in the cord? (f) Could you anticipate the answers to parts (c), (d), and (e) without first doing part (b)? Explain. Figure P1.84arrow_forwardA 600 N man stands on a bathroom scale in an elevator. As the elevator starts moving, the scale reads 800 N. (a) Find the magnitude and direction of the acceleration. (b) What is the acceleration if the scale reads 450 N? (c) If the scale reads zero, should the man worry? Explain.arrow_forward
- College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningPhysics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning
- University Physics Volume 1PhysicsISBN:9781938168277Author:William Moebs, Samuel J. Ling, Jeff SannyPublisher:OpenStax - Rice UniversityCollege PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax CollegePrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning