Linear motion present

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(BB101 ) ENGINEERING SCIENCE BY NUR ELYANI BINTI MUSA JMSK

Transcript of Linear motion present

  • 1.NUR ELYANI BINTI MUSA JMSK

2. Hair Raiser Roller Coaster POV Ocean Park Hong Kong B M Floorless On-Ride - 3.wmv 3. Define scalar and vector quantities. Define linear motion Define uniform and non-uniform motion. Describe distance, displacement, speed, velocity, average velocity, instantaneous velocity, acceleration and deceleration. Apply the concept of linear motion in solving the related problems by using formula Illustrade velocity time graph. Determine the velocity, acceleration and displacement from the graphs. 4. Objective Define scalar quantity and vector quantityDefinition Quantity which has magnitude only. Example Distance, speed, Length, Time, density 5. Objective Define scalar and vector quantityDefinition - Quantity which have both magnitude and direction. Example Displacement, velocity, Force, Acceleration 6. Objective Define linear MotionLinear motion is the motion of an object, moving in a straight line or path. The movement of any object depend on frequent questions: How far ! How fast ! Which direction ! 7. Objective Define uniform motion Define non linear motionDefinitionUniform motion is reaching and maintaining its maximum speed on a straight line. Example A falling coconut A car moving in same speed in a straight line 8. Objective Define uniform motion Define non linear motionDefinitionNon linear motion that undergoes a change in velocity, either by changing speed or changing direction. Example A roller coaster ride A snake crawling 9. Objective Describe distance , displacement, speed, velocity, average velocity, instantaneous velocity, acceleration & decelerationDistance (How far) Definition is total route taken from one place into another place. Scalar Quantity because it has magnitude only SI unit is meter Displacement Definition is distance along with direction Vector quantity because it has both magnitude & direction. SI unit is meter (m) 10. DistanceAn aeroplane is flying from Airport A to Airport B with a long distance about 350km without direction.DisplacementBut if the aeroplane use a direction move towards Airport B, its displacement is 100km. 11. Speed Objective Describe distance , displacement, speed, velocity, average velocity, instantaneous velocity, acceleration & decelerationVelocity Speed is the rate of Velocity is the rate of change of distance. change of displacement. Speed is scalar quantity. Velocity is vector quantity. Speed = Distance, m Time, s SI unit is meter per second (ms-1).Velocity = Displacement, m Time, s SI unit is meter per second (ms-1). 12. Objective Describe distance , displacement, speed, velocity, average velocity, instantaneous velocity, acceleration & decelerationAverage Velocity Instantaneous Velocity Average velocity is Instantaneous for velocity of entire Velocity is velocity of trip. an object at the particular instant or time. 13. Acceleration Objective Describe distance , displacement, speed, velocity, average velocity, instantaneous velocity, acceleration & decelerationDeceleration.Acceleration is the rate change of Deceleration is the rate change velocity. of velocity that has negative value. Acceleration is vector quantity. (Slowing down) Acceleration = v - u Acceleration = v - u t t Where : Where : v = Final velocity (last high value) v = Final velocity (last value) u = Initial velocity(start to moving) u = Initial velocity(start to slowing t = time down) t = time SI unit is ms-2. Example : A car starts to move slowly after max speed. Example : A car starts to move fast SI unit is ms-2. From rest or low speed. *Formula same as acceleration. 14. Objective Describe distance , displacement, speed, velocity, average velocity, instantaneous velocity, acceleration & decelerationA student walks to the south for 30 m, then to the east for 40 m and finally to the north for 30 m before he stops to rest. The total time taken by the student for the whole journey is 40 seconds. a) What is the total distance travelled? b) What is the displacement of the student? c) What is the average speed of the student and his velocity? Solution Total distance = 30 m + 40 m + 30 m Rest place Starting Point = 100 m Displacement = 40 m to the east. Displacement 30 m30 m40 mAverage speed = 100 m 40 = 2.5ms -1 Velocity = 40 m = 1.0 ms 40 s 15. Objective Describe distance , displacement, speed, velocity, average velocity, instantaneous velocity, acceleration & decelerationIn a car test, the velocity of a car increases uniformly from rest to 30 ms-1 in 15 seconds. What is the acceleration of the car? Solution: Acceleration = Final Velocity, v Initial Velocity, u Time taken, t = 30 ms -1 0 ms-1 15 s = 2 ms-2 16. Quantity Apply the concept of linear motion in solving the related problems by using formulaSymbolUnitDistance/displacementsmTimetsInitial VelocityumsFinal VelocityvmsAcceleration/decelerationamsEquationUnitPhysic Quantity DisplacementVelocity AccelerationM (Metre) V = u + atms (metre/second)A=v u tms (metre/second) 17. Apply the concept of linear motion in solving the related problems by using formulaA driver accelerates his car from 20 ms. What is his velocity after 8 seconds ? 3 quantities are knownSolution : U = 20msFirst trialSecond triala = 2 ms ? x v = u +2 a s ? v=u+at v = 20 + 2 (8) = 36 mst = 8sv=?Unable to calculate, because only two quantity are known 18. v, m sIllustrade velocity time graph. Increasing velocity Constant/Uniform acceleration v, m st (s) Constant/Uniform velocity Zero acceleration v, m st (s) Decreasing velocity Constant/Uniform deceleration t (s) 19. Objective Describe distance , displacement, speed, velocity, average velocity, instantaneous velocity, acceleration & decelerationExercise A. A cow moves 3 meter to the east and then 4 meter to the north. Find the : i. Total distance moved by the cow ii. Displacement of the cow B.A runner runs from the starting line and achieves a velocity of 18m/s in 3 seconds. Calculate his acceleration. 20. Objective Describe distance , displacement, speed, velocity, average velocity, instantaneous velocity, acceleration & decelerationA cow moves 3 meter to the east and then 4 meter to the north. Find the : i) Total distance moved by the cow ii) Displacement of the cow Solution : C 4mA3mB C5m A3m4m BThe total distance moved by the cow = Length of AB + Length of BC = 3m + 4m = 7m AC = AB+ BC = 3+ 4 = 9+ 16 = 25 = 5m 21. Objective Describe distance , displacement, speed, velocity, average velocity, instantaneous velocity, acceleration & decelerationA runner runs from the starting line and achieves a velocity of 18m/s in 3 seconds. Calculate his acceleration. Solution u = o m/s v = 18 m/s t = 3s a=vu t a = 18 0 3 a = 6 m/s 22. Q1(d)A.Objective Describe distance , displacement, speed, velocity, average velocity, instantaneous velocity, acceleration & decelerationA runner runs from the starting line and achieves a velocity of 20 m/s in 2.6 seconds. (CLO3)i.Calculate his acceleration (2 marks)ii.If the acceleration is constant, calculate the displacement traveled in 6.5 second. ( 2 marks) 23. A. Objective Describe distance , displacement, speed, velocity, average velocity, instantaneous velocity, acceleration & decelerationA runner runs from the starting line and achieves a velocity of 20 m/s in 2.6 seconds. (CLO3)i.Calculate his acceleration (2 marks) v = u + at 20 = 0 + a(2.6) ..(1 m) a = 202.6 a = 7.69 m/s (1 m) 24. A runner runs from the starting line and achieves a velocity of 20 m/s in 2.6 seconds. (CLO3) ii If the acceleration is constant, calculate the displacement traveled in 6.5 second. A.Objective Describe distance , displacement, speed, velocity, average velocity, instantaneous velocity, acceleration & deceleration(2 marks) s = u t + 1 at 2 s = 0 + 1 ( 7.69) (6.5) ( 1 m) 2 s = 162.45 m ..( 1 m) 25. Q1(d)Objective Describe distance , displacement, speed, velocity, average velocity, instantaneous velocity, acceleration & decelerationA car starting from rest and accelerates at a constant acceleration of 5 m/s for 10 s. The car then travels at a constant velocity for 15 s. the brakes are then applied and the car stops in 5 s. i. Sketch a velocity- time graph for the whole journey a=vu t 5=v0 10 v = 50 m/sv (m/s)500102530t (s) 26. Achieved the objectiveDefine scalar and vector quantities. Define linear motion Define uniform and non-uniform motion. Describe distance, displacement, speed, velocity, average velocity, instantaneous velocity, acceleration and deceleration. Apply the concept of linear motion in solving the related problems by using formula Illustrade velocity time graph. Determine the velocity, acceleration and displacement from the graphs. 27. shows a person move with 2ms-1 along a circular path. The magnitude of the quickness is the same, but the direction keeps changing. Hence we say that the velocity of this person keep changing when he moves through the path. 28. www.youtube.com Modul BB101 Engineering Science (JMSK)