Volume = area × rainfall = 500 km² × 800 mm = 500,000,000 m³.

Discharge = Width × Depth × Velocity. Assuming velocity = 1 m/s, Depth = Discharge / (Width × Velocity) = 1500 m³/s / (25 m × 1 m/s) = 60 m.

Distance = speed × time = 3 m/s × 7200 s = 21600 m.

Soil eroded = Erosion rate × Area = 5 tons/hectare/year × 100 hectares = 500 tons/year.

Discharge = area × velocity = 150 m² × 4 m/s = 600 m³/s.

Average discharge = Total discharge / Drainage area. Assuming total discharge = 250 m³/s, Average discharge = 250 m³/s / 500 km² = 0.5 m³/s.

Discharge = Velocity × Area. Area = Width × Depth = 10 m × 3 m = 30 m². Discharge = 2 m/s × 30 m² = 60 m³/s.

Cross-sectional area = Width × Depth = 15 m × 2 m = 30 m².

The percentage of clay is given as 30%.

At the equinox, the sun is directly overhead at the equator, which is at 0 degrees latitude.

Each hour corresponds to 15 degrees. Therefore, 3 hours ahead means 3 * 15 = 45 degrees east of GMT, which is 45°E.

A time difference of 4 hours corresponds to 4 * 15 = 60 degrees of longitude.

The Earth is 360 degrees, and if each time zone is 15 degrees, then 360 / 15 = 24 time zones.

120 degrees West corresponds to GMT-8, as each 15 degrees represents one hour.

120°W corresponds to 120 / 15 = 8 hours behind GMT, hence -8 hours.

The total distance is 60° + 60° = 120°. At 15° per hour, it will take 120 / 15 = 8 hours.

Total sediment = Sediment capacity × Flow rate × Time = 200 kg/m³ × 10 m³/s × 3600 s = 7200000 kg.

New flow rate = Original flow rate + (20% of Original flow rate) = 50 m³/s + (0.2 × 50 m³/s) = 60 m³/s.

Flow in 10 minutes = 500 m³/s × 600 s = 300,000 m³ = 300,000,000 L.

Sediment transported = sediment load × flow rate × time = 200 kg/m³ × 10 m³/s × 3600 s = 720,000 kg.

Erosion = rate × time = 2 m/year × 5 years = 10 m.

At 45 degrees East, it is 45/15 = 3 hours ahead. Therefore, it is 12:00 PM + 3 hours = 3:00 PM.

Each degree of longitude represents 4 minutes of time. 75°W = 75 * 4 = 300 minutes = 5 hours. Therefore, it is 12:00 noon - 5 hours = 7:00 AM.

New Delhi is 77°E, which is 77 * 4 = 308 minutes = 5 hours and 8 minutes ahead of GMT. Therefore, 3:00 PM - 5:08 = 9:30 AM.

New York is 5 hours behind London, so 3:00 PM + 5 hours = 8:00 PM in London.

The atmospheric pressure of 1013 hPa is equivalent to 760 mmHg.

A pH greater than 7 is considered alkaline.

Using a dew point calculator or approximation, the dew point at 80% relative humidity and 25°C is approximately 22°C.

Using the formula for dew point, the approximate dew point at 80% humidity and 30°C is around 20°C.

Vertical drop = Distance × Slope = 2000 m × (1/1000) = 2 m.