Transcript P2 326KB
Speeding up and slowing down f = ma Terminal velocity 1. What are the four forces acting on an aeroplane. 2. How do each of the four forces act on an airplane in flight? (Which direction does each force push or pull on the airplane in flight?) 3. Which force on an airplane is always directed toward the centre of the earth? 4. Which force is responsible for moving the airplane forward? 5. Which force do the wings of the airplane generate? For questions 7-10, predict what effect the following flight conditions would have on the plane. (Would the plane rise, fall, slow, or accelerate?) 7. Drag > Thrust 8. Lift > Weight 9. Thrust > Drag 10.Weight > Lift 11.Define balanced and unbalanced. 12.During a flight when we are cruising at a specific altitude, the four forces are balanced. At which points during a flight are the forces unbalanced? 13.Define Newton's First Law of Motion. 14.In your own words, explain how Newton's First Law of Motion explains the motion of a cruising airplane. Force, mass, acceleration The diagram shows an athlete accelerating. The athlete has a mass of 65 kg and produces a constant forward force of 364 N. (i) Write down the equation that links acceleration, force and mass. (1 mark) (ii) Calculate the maximum acceleration of the athlete. Show clearly how you work out your answer. (2 marks) (b) The athlete’s forward force is the same throughout the race. Explain why the acceleration of the athlete decreases to zero during the race. (2 marks) 1. A car of mass 900 kg has an engine which exerts a force of 450N on the car. Assuming 100% efficiency, what is the minimum amount of time needed for the car to accelerate from 0 to 10 m/s? 2. A car accelerates from 0 m/s to 10 m/s in 50 seconds. What is the acceleration? 3. A train decelerates from 30 m/s to 25 m/s in 2 minutes. What is the acceleration? (Answer to 2 s.f.) Terminal Velocity 0 seconds 10 seconds Fair = 400N Fweight = F weight 1000N Fweight = 1000N 20 seconds Fair = 800N Fweight = 1000N 30 seconds Fair = 1000N Fweight = 1000N 1. Define the term terminal velocity. 2. In each of the above diagrams what is the resultant force? 3. Given that the acceleration of the parachutist is constant within all of the time frames, plot a speed time graph for the parachutist. (Use the graph paper over the page)