Concept explainers
(a) Calculate the force needed to bring a 950-kg car to rest from a speed of 90.0 km/h in a distance of 120 m (a fairly typical distance for a non-panic stop). (b) Suppose instead the car hits a concrete abutment at full speed and is brought to a stop in 2.00 m. Calculate the force exerted on the car and compare it with the force found in part (a).
Trending nowThis is a popular solution!
Learn your wayIncludes step-by-step video
Chapter 7 Solutions
College Physics
Additional Science Textbook Solutions
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)
Sears And Zemansky's University Physics With Modern Physics
Conceptual Physics (12th Edition)
Physics for Scientists and Engineers: A Strategic Approach, Vol. 1 (Chs 1-21) (4th Edition)
University Physics Volume 1
University Physics with Modern Physics (14th Edition)
- A particle moves in a medium under the influence of a retarding force equal to mk(υ3+ a2υ), where k and a are constants. Show that for any value of the initial speed the particle will never move a distance greater than π/2kaand that the particle comes to rest only for t → ∞.arrow_forwardA cart is set rolling across a level table, at the same speed on every trial. If it runs into a patch of sand, the cart exerts on the sand an average horizontal force of 6 N and travels a distance of 6 cm through the sand as it comes to a stop. It instead the cart runs into a patch of gravel on which the can exerts an average horizontal force of 9 N, how far into the gravel will the cart roll before stopping? (a) 9 cm (b) 6 cm (c) 4 cm (d) 3 cm (e) none of those answersarrow_forwardA car’s bumper is designed to withstand a 4.0-km/ h (1.1-m/s) collision with an immovable object without damage to the body of the car. The bumper cushions the shock by absorbing the force over a distance. Calculate the magnitude of the average force on a bumper that collapses 0.200 m while bringing a 900-kg car to rest from an initial speed of 1.1 m/s.arrow_forward
- Review. A 3.00-kg block starts from rest at the top of a 30.0 incline and slides a distance of 2.00 m down the incline in 1.50 s. Find (a) the magnitude of the acceleration of the block, (b) the coefficient of kinetic friction between block and plane, (c) the friction force acting on the block, and (d) the speed of the block after it has slid 2.00 m.arrow_forwardA worker pushes a 35.0-kg package on a horizontal roller-belt conveyor until it reaches a certain speed. The package then coasts on the horizontal conveyor, all the while slowing down, until it comes to a complete stop after moving 1.20 m. While the package is coasting on the conveyor, the opposing friction force averages 6.00 N. Use the WET to find the speed of the package after the worker pushes it and just as it begins to coast. 0.625 m/s 0.759 m/s 0.600 m/s 0.510 m/s 0.802 m/s 0.641 m/sarrow_forwardCalculate the force (in N) needed to bring a 1050 kg car to rest from a speed of 80.0 km/h in a distance of 100 m (a fairly typical distance for a non-panic stop). N (b) Suppose instead the car hits a concrete abutment at full speed and is brought to a stop in 2.00 m. Calculate the force exerted on the car and compare it with the force found in part (a). force in (b) force in (a) =arrow_forward
- a 925-kg pick up decelerates to rest from a speed of 97.5 km/h in a distance 125 m. Suppose the pick up is initially traveling in the positive direction. suppose instead of breaking that the pick up hits a concrete abutment at full speed is brought up to a stop at 2.0 m. Calculate the force in newtons exerted on the pickup in this case.arrow_forwardA person jumps from the roof of a house 3.9-m high. When he strikes the ground below, he bends his knees so that his torso decelerates over an approximate distance of 0.70 m. If the mass of his torso (excluding legs) is 42 kg. find (a) his velocity just before his feet strike the ground, and (b) the average force exerted on his torso by his legs during deceleration.arrow_forward(a) Calculate the force needed to bring a 850 kg car to rest from a speed of 95.0 km/h in a distance of 105 m (a fairly typical distance for a nonpanic stop). N(b) Suppose instead the car hits a concrete abutment at full speed and is brought to a stop in 2.00 m. Calculate the force exerted on the car and compare it with the force found in part (a), i.e. find the ratio of the force in part(b) to the force in part(a). (force in part (b) / force in part (a))arrow_forward
- Calculate the force needed to bring a 450-kg canoe to rest from a speed of 10.8 km/h in a distance of 120 m. Express your answer in N.arrow_forward(a) Calculate the force needed to bring a 950 kg car to rest from a speed of 95.0 km/h in a distance of 110 m (a fairly typical distance for a nonpanic stop).N(b) Suppose instead the car hits a concrete abutment at full speed and is brought to a stop in 2.00 m. Calculate the force exerted on the car and compare it with the force found in part (a), i.e. find the ratio of the force in part(b) to the force in part(a).(force in part (b) / force in part (a))arrow_forwardYou went on a drive late at night after having a fun party with the member of your company when you accidentally hit another car. The investigator observes a skid marks 25m long left by your 1500kg car. Your car skidded to stop on a concrete highway having a coefficient of kinetic friction with the tires of 0.80. Estimate your car's speed at the beginning of the skid?arrow_forward
- Classical Dynamics of Particles and SystemsPhysicsISBN:9780534408961Author:Stephen T. Thornton, Jerry B. MarionPublisher:Cengage LearningPhysics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningUniversity Physics Volume 1PhysicsISBN:9781938168277Author:William Moebs, Samuel J. Ling, Jeff SannyPublisher:OpenStax - Rice University