Water Is Flowing in a Drainage Channel of Rectangular Cross-Section $1000 \mathrm {~kg} / \mathrm { m } ^ { 3 }$

Water is flowing in a drainage channel of rectangular cross-section. The width of the channel is 15 m, the depth of water is 8.0 m, and the speed of the flow is 2.5 m/s. What is the mass flow rate of the water? The density of water is $1000 \mathrm {~kg} / \mathrm { m } ^ { 3 }$

A) $3.0 \times 10 ^ { 2 } \mathrm {~kg} / \mathrm { s }$
B) $2.0 \times 10 ^ { 5 } \mathrm {~kg} / \mathrm { s }$
C) $2.0 \times 10 ^ { 3 } \mathrm {~kg} / \mathrm { s }$
D) $3.0 \times 10 ^ { 3 } \mathrm {~kg} / \mathrm { s }$
E) $3.0 \times 10 ^ { 5 } \mathrm {~kg} / \mathrm { s }$