Recall from JC maths science Speed and distance are scalars We use the vector versions velocity and displacement 1 Solve Problems About Linear Motion only works for constant or average velocity ID: 534861
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Solve Problems About Linear Motion
Recall from JC maths / science:Speed and distance are scalarsWe use the vector versions, velocity () and displacement ():
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Solve Problems About Linear Motion
only works for constant (or average) velocity.Usually we deal with acceleration:
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We can also find average velocity using:
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Solve Problems About Linear Motion
e.g. The velocity of a car changes from 10 m s-1 East to 40 m s-1 East in 5 seconds. Calculate its average acceleration.e.g. The speed of a bicycle moving in a straight line decreases from 15 m s-1 to 3 m s -1 in 6 seconds. Find its average acceleration.e.g. The velocity of a car changes from 5 m s-1 East to 9 m s-1 West in 2.5 seconds. Find the average acceleration of the car.3Slide4
Solve Problems About Linear Motion
We can derive three more equations about accelerating bodies:
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Solve Problems About Linear Motion
Each problem gives some of these quantities and requires others.Use a uvast table to keep track:e.g. The velocity of a car changes from 10 m s-1 East to 40 m s-1 East in 5 seconds. Calculate its average acceleration.5uvast1040
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Solve Problems About Linear Motion
A car travels along a straight level road.It passes a point P with a speed of 8 m s-1 and accelerates uniformly for 12 seconds to a speed of 32 m s -1. It then travels at a constant speed of 32 m s-1 for 7 seconds.Finally the car decelerates uniformly from 32 m s-1 to rest at a point Q. The car travels 128 m while decelerating.Find:the acceleration and deceleration|PQ|, the distance from P to Q.the speed of the car when it is 72 m from Q.6Slide7
Solve Problems About Linear Motion
Velocity-time graphs are used to solve problems about motion.If velocity is plotted on the y-axis and time is plotted on the x-axis,The area under the graph represents the distance travelled.The slope of a line represents the acceleration of the object for that stage of the journey.7Slide8
Solve Problems About Linear Motion
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Solve Problems About Linear Motion
A car travels from p to q along a straight level road.It starts from rest at p and accelerates uniformly for 5 seconds to a speed of 15 m/s.It then moves at a constant speed of 15 m/s for 20 seconds.Finally the car decelerates uniformly from 15 m/s to rest at q in 3 seconds.Draw a speed-time graph of the motion of the car from p to q.Find the uniform acceleration of the car.Find the uniform deceleration of the car.Find |pq|, the distance from p to q.Find the speed of the car when it is 13.5 metres from p.9Slide10
Solve Problems About Linear Motion
Four points a, b, c and d lie on a straight level road.A car, travelling with uniform retardation, passes point a with a speed of 30 m/s and passes point b with a speed of 20 m/s.The distance from a to b is 100 m. The car comes to rest at d.Find the uniform retardation of the carthe time taken to travel from a to bthe distance from b to dthe speed of the car at c, where c is the midpoint of [bd].10Slide11
Solve Problems About Linear Motion
A car travels along a straight level road. It passes a point p at a speed of 10 m/s and accelerates uniformly for 5 seconds to a speed of 30 m/s. It then moves at a constant speed of 30 m/s for 9 seconds. Finally the car decelerates uniformly from 30 m/s to rest at point q in 6 seconds. Findthe acceleration the deceleration pq , the distance from p to q the average speed of the car as it travels from p to q. 11