S.3 Physics Motion Caltec S.3

S.3 MOTION NOTES 2020 1 TOPIC : MECHANICS AND PROPERTIES OF MATTER General Objective: The learner should be able to use knowledge of motion and its equations to understand relationship between force, energy and motion. SUB -TOPIC : Linear motion SPECIFIC OBJECTIVES The earner shou ld be able to; • Define speed and average speed. • Calculate speed and average speed. • Define displacement , velocity and acceleration. • Define uniform velocity and uniform acceleration. • Draw and interpret velocity graphs for linear motion. • Use equati ons of motion to solve numerical problems. • Use ticker -timer t, find velocity and acceleration. • Define acceleration due to gravity, g. • Describe a simple experiment to determine, g. LINEAR MOTION This involves study of motion of a body in a straight l ine. Distance This is the total length of pa th travelled by a body. Or Is the measurement along the exact path followed by a moving body. The SI unit of distance is metre (s) Displacement This is the distance moved in a specified direction. If stu dent followed the path from Labs, she would cover a distance of 120m. However, if she moved in a straight line, she would cover a displacement of 70 m. If the student moved from Kivebulaya house to the Laboratory and back to the house along the path, she would ha ve covered a total distance of 240 m, but her resultant displacement would be 0 m. So, displacement is a vector becaus e it is described by both magnitude and direction. On the other hand, distance is a scalar. Speed Speed is the rate of change o f distance with time. Speed =distance time taken S.3 MOTION NOTES 2020 2 Its SI unit is metre per second (ms−1). It is a …