【单选题】某液体在内径为 d 1 的水平管路中稳定流动,其平均流速为 u 1 ,当它以相同的体积流量通过等长的内径为 d 2 (d 2 =d 1 /2) 的管子时,则其流速为原来的 __________ 。
【单选题】某液体在内径为d1的水平管路中稳定流动,其平均流速为u0,当它以相同的体积流量通过等长的内径为d2(d2/d1=1/2)的管子时,若流体为层流,则压降△p为原来的 倍。
【单选题】某液体在内径为 d1的水平管路中稳定流动,其平均流速为u1, 当它以相同的体积流量通过等长的内径为d2(d2=d1/2)的管子时,则其压强降为原来的____倍。
【单选题】某液体在内径为 d 1 的水平管路中稳定流动,其平均流速为 u 1 ,当它以相同的体积流量通过等长的内径为 d 2 (d 2 =d 1 /2) 的管子时,则其流速为原来的 _____ 。
【单选题】Why did Shaefer put the paper under glass?
A.
To prevent Rosa from feeling the print.
B.
To stop the reflection of heat.
C.
To make things as difficult as possible.
D.
To stop her from cheating.
【单选题】某液体在内径为 d1的水平管路中稳定流动,其平均流速为u1, 当它以相同的体积流量通过等长的内径为d2(d2=d1/2)的管子时,则其流速为原来的____倍。
【简答题】某液体在内径为d1的水平管路中稳定流动,其平均流速为u1,当它以相同的体积流量通过等长的内径为d2(d2=d1/2)的管子时,若流体为层流,则压降Dp为原来的 倍。
【单选题】某液体在内径为D1的水平管路中稳定流动,其平均流速为u1,当它以相同的体积流量通过等长的内径为D2(D2=D1/2)的管子时,若流体为层流,则压降ΔPf为原来的()倍。
【单选题】Chapter3: Why did Stevie Morris’s teacher ask him to help her find a mouse that was lost in the classroom?
A.
Because Stevie Morris was unafraid.
B.
Because she knew Stevie Morris wanted to find the mouse.
C.
Because she appreciated that Stevie Morris had a remarkable pair of ears.
【简答题】某液体在内径为d1的水平管路中稳定流动,其平均流速为u1,当它以相同的体积流量通过某内径为d2(d2=d1/2)的管子时,流动为层流时,管子两端压力降△Pf 为原来的 倍。