# Math Help - find volume

1. ## find volume

Hello everybody,
can anyone help me plz with this problem?

a river, runnung between parallel banks, is 20 m wide. the depth, y metres, of the river measured at point x metres from one bank is given by formula
y = 1/10 * x *√(20-x), 0≤ x ≤20.
the table below, giving values of y to 3 decimal places.
x: 0 4 8 12 16 20
y: 0 1.600 2.771 2.262 3.200 0
by using the trapezium rule with all the values in the table to estimate the cross-area of the river we found A = 39.332
given that the cross-sectional area is constant and that the river is flowing uniformly at 2 m s-1
Q: estimate, in m3, the volume of water flowing per minute, giving your answer to 3 significant figures.

Thanks

Hello everybody,
can anyone help me plz with this problem?

a river, runnung between parallel banks, is 20 m wide. the depth, y metres, of the river measured at point x metres from one bank is given by formula
y = 1/10 * x *√(20-x), 0≤ x ≤20.
the table below, giving values of y to 3 decimal places.
x: 0 4 8 12 16 20
y: 0 1.600 2.771 2.262 3.200 0
by using the trapezium rule with all the values in the table to estimate the cross-area of the river we found A = 39.332
given that the cross-sectional area is constant and that the river is flowing uniformly at 2 m s-1
Q: estimate, in m3, the volume of water flowing per minute, giving your answer to 3 significant figures.

Thanks
Lets assume your estimate for the crossectional area of the river is correct, then the water in a length of river equal to $2 \times 60$ metres will flow past a point in $1$ minute (that is $60$ seconds worth of $2$ m/s). Multiply this by the crossectional area and you will have the flow rate in cubic metres per minute.

RonL