#### Transcript jeopardy_Final2 - Decker

Chapter 11 Chapter 12 Chapter 13 Chapter 14 Phys. Sci. Hodgepodge 100 100 100 100 100 200 200 200 200 200 300 300 300 300 300 400 400 400 400 400 500 500 500 500 500 Speed is the ratio of the distance an object moves to… the amount of time needed to travel the distance Suppose you increase your walking speed from 2 m/s to 8 m/s in a period of 2 seconds. What is your acceleration? 3 m/s2 Two or more velocities add by… vector addition A person in an airplane is at rest relative to what? Anything inside the airplane (seat, neighbor…) You drive 1000 m in 60 sec and then remain at rest for 40 sec. What is your average speed? 10 m/s The SI unit for force is… the Newton Projectile motion is caused by… forward motion and the downward force of gravity What is conserved when 2 objects collide in a closed system? momentum The centripetal force acting on the moon continuously changes its… direction Name the 4 universal forces. Electromagnetic Gravitational Weak & Strong Nuclear A hydraulic lift (like on a dump truck) is an example of whose principle? Pascal’s Principle Where would you experience greater fluid pressure? at the bottom of a lake that is 10 m deep or 10 m down into the ocean The pressure would be the same in both places. A boulder weighs 2000 N. When submerged in water, it weighs 1450 N. What is the buoyant force exerted by the water on the boulder? 550 N Define lift. Upward (or downward) force due to pressure differences. Example: airplane wing Name something that is a fluid and something that is not. Example: Hydrogen = fluid Wood = not fluid The efficiency of a machine is always less than 100% because… FRICTION! What ways can a machine make work easier for you? Change the direction of a force Change the distance over which the force must be applied Change the size of the force The SI unit for power is the… Watt The distance over which YOU exert a force on a machine is called… Input distance You lift a 160 N box 1 m in half a second. What power did you produce? Power = work/time Power = (force*distance)/time Power = (160N*1m)/.5 sec Power = 320N*m/sec Power = 320J/sec Describe a vector. Represented by an arrow. Shows magnitude (size) and direction. 5m NE If a machine reduces the force it takes to do a task, what will happen to the distance over which you’ll have to exert that force? The distance will be large Do you have buoyant force acting on you right now? Yes, the air around us is a fluid and we are “submerged” in it. How is the pressure by a fluid exerted at any given depth? Equally in all directions What is a compound machine? A machine that is made of up two or more simple machines.