行李在傳送帶上加速，設(shè)加速度大小為a，加速的時(shí)間為t₁
a=

f

m

=μg=0.2×10m/s²=2m/s²               
所以t₁=

v

a

=

4

2

s=2s                             
所以勻加速運(yùn)動(dòng)的位移為：s=

1

2

at12=

1

2

×2×4m=4m                 
行李隨傳送帶勻速前進(jìn)的時(shí)間t₂=

L?s

v

=

20?4

4

s=4s                       
行李箱從A傳送到B所需時(shí)間
t=t₁+t₂=2s+4s=6s                         
答：物體經(jīng)過(guò)6s被傳送到B端．