Question

Shin

求解

76. At time t= 0 a car has a velocity of 16 m/s. It slows down with an acceleration given
by -0.50t, in m/s² for t in seconds. At the end of 4.0 s it has traveled:
0
12 m
9=-052 = √²-025²
C)
14 m
D) 25 m
E) 59 m
E
A)
B)
77. The graph represents the straight line motion of a car. How far does the car travel
between t = 2 seconds and t = 5 seconds?
D
v (m/s)

Answer 1

Labman 003

從題目得知 a=-0.5t
積分得速度v=-0.25t^2+constant
題目給出初始條件t=0，v=16，故得知constant=16
再將速度函數v=-0.25t^2+16 積分得到位移函數 x=-1/12 t^3+16t+constant*
因為題目問位移，初位置可視為0，故constant*=0
將t=4 帶入 位移函數 x=-1/12(t^3)+16t ，得x=58.67