Ch.5 Motion Graph (運動圖表)

4.2 Velocity-time Graph (速度-時間綫圖) time t velocity v The velocity-time graph (v-t graph) of uniform motion (constant velocity) is a horizontal line. 2

v1 = velocity of object A v2 = velocity of object B v1 > v2 velocity v time t A B v1 v2 v1 = velocity of object A v2 = velocity of object B v1 > v2 3

Displacement = Area of v-t graph velocity v time t v t Displacement = Area of v-t graph 4

5.1 Velocity-time Graph (速度-時間綫圖)

5.1 7

velocity = 6 m s-1 8

What is the displacement of the man at t = 40 s? 9

displacement = area = (6)(40) = 240 m What is the displacement of the man at t = 40 s? displacement = area = (6)(40) = 240 m 10

5.2

5.2 D

5.3

5.3 D

5.4

a = slope = 8 ÷ 40 = 0.2 m s-2

s = area = 0.5 × 8 × 40 = 160 m

5.5

(i) a = slope = 0 (ii) a = slope = (0-18) ÷ (20-10) = -1.8 ms-2

(i) s = area = (10)(18) = 180 m

(ii) s = area = 0.5 × 10 × 18 = 90 m