Concept explainers
Catapulting mushrooms. Certain mushrooms launch their spores by a catapult mechanism. As water condenses from the air onto a spore that is attached tothe mushroom, a drop grows on one side of the spore and a film grows on the other side. The spore is bent over by the drop’s weight, but when the film reaches the drop, the drop’s water suddenly spreads into the film and the spore springs upward so rapidly that it is slung off into the air. Typically, the spore reaches a speed of 1.6 m/s in a 5.0 µm launch; its speed is then reduced to zero in 1.0 mm by the air. Using those data and assuming constant accelerations, find the acceleration in terms of g during (a) the launch and (b) the speed reduction.
Want to see the full answer?
Check out a sample textbook solutionChapter 2 Solutions
Fundamentals of Physics Extended
Additional Science Textbook Solutions
Campbell Biology in Focus (2nd Edition)
Fundamentals Of Thermodynamics
Cosmic Perspective Fundamentals
Anatomy & Physiology (6th Edition)
Chemistry: An Introduction to General, Organic, and Biological Chemistry (13th Edition)
Campbell Essential Biology with Physiology (5th Edition)
- To give a pet hamster exercise, some people put the hamster in a ventilated ball andallow it roam around the house(Fig. P13.66). When a hamsteris in such a ball, it can cross atypical room in a few minutes.Estimate the total kinetic energyin the ball-hamster system. FIGURE P13.66 Problems 66 and 67arrow_forwardDandelion seeds have a plume made of thin filaments that create a very large drag coefficient due to subtle aerodynamics as the air moves through and past the plume. The slower terminal speed and longer time in the air provide greater dispersal than would be possible for simple spherical seeds. A 0.63 mg seed has a plume with a cross-section area of 13 mm, and it falls with a terminal speed of 40 cm/s.arrow_forwardA horizontal water jet of constant velocity V from a stationary nozzle impinges normally on a vertical flat plate that rides on a nearly frictionless track. As the water jet hits the plate, it begins to move due to the water force. What is the highest velocity the plate can attain? Explain.arrow_forward
- A person of mass m stands on a rope ladder that is hanging from a freely floating balloon of mass M. The balloon is initially at rest with respect to the ground. (The buoyant force on the personballoon system is countering the force of gravity.) a. In what direction will the balloon move if the person starts to climb the rope ladder at constant velocity v relative to the ladder? b. At what speed will the balloon move if the person starts to climb the rope ladder at constant velocity v relative to the ladder?arrow_forwardA suspicious physics student watches a stunt performed at an ice show. In the stunt, a performer shoots an arrow into a bale of hay (Fig. P11.24). Another performer rides on the bale of hay like a cowboy. After the arrow enters the bale, the balearrow system slides roughly 5 m along the ice. Estimate the initial speed of the arrow. Is there a trick to this stunt? FIGURE P11.24arrow_forwardWhen a person feels that he is about to fall, he will often put out his hand to try to break the fall. Explain why this natural reaction usually leads to bruises or minor broken bones such as in the wrists instead of major broken bones such as the skull.arrow_forward
- In a two-dimensional tug-of-war, Alex, Betty, and Charles pull horizontally on an automobile tire at the angles shown in the picture. The tire remains stationary in spite of the three pulls. Alex pulls with force F→A of magnitude 202 N, and Charles pulls with force F→C of magnitude 189 N. Note that the direction of F→C is not given. What is the magnitude of Betty's force F→B if Charles pulls in (a) the direction drawn in the picture or (b) the other possible direction for equilibrium?arrow_forwardYour answer is partially correct. African elephants are the largest land animals. They consume approximately 10% of their body weight in food each day, which for an adult male, can be 1000 lb. of vegetation! Their diet consists mostly of grasses, bamboo, tree bark, and fruit. They also like to dine on tree leaves. To reach them, they often stand up on their hind legs and extend their trunks (see the figure). The elephant in the figure is in equilibrium. The location of the elephant's center of mass is shown, and the axis of rotation has been chosen to correspond to the hip joint. The forces in the elephant's free-body diagram are shown, and there is a static friction force between the elephant's back feet and the ground. Use the following information and calculate the magnitude of the tension in the elephant's trunk T (m = 4540 kg, FN = 'fs=133 cm, rcg = 76.0 cm, r = 229 cm). Number 1103.035 +x Axis of rotation Units N 165⁰ 60⁰ W =FN 30° FN 10° Michael Poliza/Caters News Agencyarrow_forwardImagine we have created layers of ice on the surface of a platform and then propped it up at an angle of 10° with the ground. This makes a ramp 10 ft long from one end to the other. We then place the 5 kg cube at the top of the ramp and let it go. How long will it take for the cube to reach the end of the 10 ft ramp?arrow_forward
- Grab a meter stick or any uniform thin piece of wood about 1m in length. (e.g. the handle of a broom with the head removed). Place your index fingers at either end so that you are holding the stick up with just two fingers. Move your fingers slowly together. Where do they end up? Describe the motion of your fingers. Explain why this happens.arrow_forwardA laborer wants to move crates containing bottles of olive oil from a truck to the ground by sliding them along a ramp. The ramp is 6 m long and is at an angle of 25°. There is friction on the ramp for the first crate. The laborer doesn’t know that there is a small leak in one of the bottles. The leak leaves a layer of oil on the ramp. The oil creates a frictionless surface for the second crate Wayne sends down the ramp. At the bottom of the ramp, the speed of the second crate (without friction) is 2.5 the speed of the first crate (with friction). Find the coefficient of kinetic friction. Hint: this is a multistep problem that is be solved using only energy equations. Do not use kinematics . Use conservation of energy and start with the frictionless case.arrow_forwardSome salvage divers are raising a rectangular box of treasure measuring1m × 1.3m × 1.9m from the bottom of the sea. They are using a cable which can handle a maximum force of 10 000 N without breaking. They raise the treasure from the bottom of the ocean at a constant speed. All goes well while the treasure is rising through the water but much to the despair of the salvors as soon as the treasure is clear of the water the cable breaks, dropping the treasure back into the briny deep. What are the maximum and minimum possible weights of the lost treasure?arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningClassical Dynamics of Particles and SystemsPhysicsISBN:9780534408961Author:Stephen T. Thornton, Jerry B. MarionPublisher:Cengage Learning
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning