ACA EXAMS SCRIPT ANSWERS AND QUESTIONS SET
A+
✔✔Kim can do the job in 6 days but if Andre will help they can finish it in 2 days. How
long will it take Andre to do the job alone? - ✔✔Answer: 3 days
✔✔Sugarcane is to be irrigated using sprinkler irrigation. The sprinkler spacing is 12.2
m while the lateral spacing is 18.3 m. The soil water holding capacity is 120 mm/m, crop
rooting depth is 1.0 m and management allowable deficit is 45%. If the irrigation period
is 12 hrs and the application efficiency is 70%, the required sprinkler discharge is. -
✔✔Answer: 0.4 lps
✔✔Determine how many liters of an 8% acid solution and how many liters of a 10%
acid solution should be mixed to obtain 10 liters of 9% acid solution. - ✔✔Answer: 5
liters of each solution
✔✔A 3-ha of cornfield is to be irrigated at a discharge of 250 lps. The average available
water holding capacity is 140 mm/m soil, the management allowable deficit is 40%, and
the rootzone depth is 0.5 m. The reference crop potential evapotranspiration is 5
mm/day and the crop coefficient is 0.8. Assuming 70% application efficiency, the
irrigation period should be. - ✔✔Answer: 1 1/3 hrs
✔✔The soil has a field capacity of 22% and a permanent wilting point of 12 %, both on
a dry mass basis. The apparent specific gravity is 1.4. If the rootzone depth is 1.0 m and
the management allowable deficit is 50%, the net application depth is. - ✔✔Answer:
70mm
✔✔The amount of pure N in a 50-kg bag of urea (46-0-0) - ✔✔Answer: 23 kg
✔✔The most hydraulically efficient trapezoidal channel section to carry a discharge of 5
m3/s on a bed material with a roughness n of 0.02 and a bottom slope of 1 in 800
should have a bottom width of. - ✔✔Answer: 1.65m
, ✔✔A concrete-lined trapezoidal canal is to carry a maximum discharge of 2.0 m3/s. The
required head loss over a horizontal distance of 1 km is 2.0 m. The side slope is to be
set at 1:1 and the permissible b/d ratio is 3. If the Manning's roughness coefficient is
0.015, the design depth required is. - ✔✔Answer: 0.56m
✔✔A farmer has 2,400 feet of fencing and wants to fence off a rectangular field that
border a straight river. He needs no fence along the river. What are the dimensions of
the field that has the largest area? - ✔✔Answer: 600 by 1,200
✔✔A 30-inch diameter 1-meter long culvert has been designed to carry a maximum
discharge of 1.7 m3/s when flowing half-full. Its roughness coefficient n is 0.014. If the
inlet and the outlet are both unsubmerged, the difference in elevation between the inlet
and the outlet should be. - ✔✔Answer: 10cm
✔✔The water duty at the farm level is 2.0lps/ha. If the application efficiency is 70% and
the conveyance efficiency is 80% the diversion water requirement is. - ✔✔Answer: 2.5
lps/ha
✔✔A triangular plot of land is to be used as a vegetable garden. The measures of the
plot are AB = 8 meters, BC = 12 meters and AC = 18 meters. Find the measure of angle
B. - ✔✔Answer: 127.2°
✔✔The mass of radium-226 is given by. Its half-life is 1,590 years. A sample radium-
226 has a mass of 1,000 mg. Find the mass after 1,000 years. - ✔✔Answer: 65 mg
✔✔The selling price P of an item is 100 - 0.02x pesos, where x is the number of items
produced per day. If the cost C of producing and selling x items is 40x + 15,000, pesos
per day, how many items should be produced and sold every day in order to maximize
the profit? - ✔✔Answer: 1, 500
✔✔A ladder 10 feet long rests against a vertical wall. If the bottom of the ladder slides
away from the wall at a rate of 1 ft/sec, how fast is the top of the ladder sliding down the
wall when the bottom of the ladder is 6 feet from the wall? - ✔✔Answer: -0.75 ft/sec
✔✔A water tank has the shape of an inverted circular cone with the base radius 2
meters and height 4 meters. If water is being pumped into the tank at a rate of 2
m3/minute, find the rate at which the water level is rising when the water is 3 meters
deep. - ✔✔Answer: 0.28 m/min
✔✔Size up the nozzle for a sprinkler irrigation system given the following: application
rate 12 mm/hr operating pressure 500 kPa, irrigated area 250 m2, discharge coefficient
0.80 - ✔✔Answer: 6.5 mm
A+
✔✔Kim can do the job in 6 days but if Andre will help they can finish it in 2 days. How
long will it take Andre to do the job alone? - ✔✔Answer: 3 days
✔✔Sugarcane is to be irrigated using sprinkler irrigation. The sprinkler spacing is 12.2
m while the lateral spacing is 18.3 m. The soil water holding capacity is 120 mm/m, crop
rooting depth is 1.0 m and management allowable deficit is 45%. If the irrigation period
is 12 hrs and the application efficiency is 70%, the required sprinkler discharge is. -
✔✔Answer: 0.4 lps
✔✔Determine how many liters of an 8% acid solution and how many liters of a 10%
acid solution should be mixed to obtain 10 liters of 9% acid solution. - ✔✔Answer: 5
liters of each solution
✔✔A 3-ha of cornfield is to be irrigated at a discharge of 250 lps. The average available
water holding capacity is 140 mm/m soil, the management allowable deficit is 40%, and
the rootzone depth is 0.5 m. The reference crop potential evapotranspiration is 5
mm/day and the crop coefficient is 0.8. Assuming 70% application efficiency, the
irrigation period should be. - ✔✔Answer: 1 1/3 hrs
✔✔The soil has a field capacity of 22% and a permanent wilting point of 12 %, both on
a dry mass basis. The apparent specific gravity is 1.4. If the rootzone depth is 1.0 m and
the management allowable deficit is 50%, the net application depth is. - ✔✔Answer:
70mm
✔✔The amount of pure N in a 50-kg bag of urea (46-0-0) - ✔✔Answer: 23 kg
✔✔The most hydraulically efficient trapezoidal channel section to carry a discharge of 5
m3/s on a bed material with a roughness n of 0.02 and a bottom slope of 1 in 800
should have a bottom width of. - ✔✔Answer: 1.65m
, ✔✔A concrete-lined trapezoidal canal is to carry a maximum discharge of 2.0 m3/s. The
required head loss over a horizontal distance of 1 km is 2.0 m. The side slope is to be
set at 1:1 and the permissible b/d ratio is 3. If the Manning's roughness coefficient is
0.015, the design depth required is. - ✔✔Answer: 0.56m
✔✔A farmer has 2,400 feet of fencing and wants to fence off a rectangular field that
border a straight river. He needs no fence along the river. What are the dimensions of
the field that has the largest area? - ✔✔Answer: 600 by 1,200
✔✔A 30-inch diameter 1-meter long culvert has been designed to carry a maximum
discharge of 1.7 m3/s when flowing half-full. Its roughness coefficient n is 0.014. If the
inlet and the outlet are both unsubmerged, the difference in elevation between the inlet
and the outlet should be. - ✔✔Answer: 10cm
✔✔The water duty at the farm level is 2.0lps/ha. If the application efficiency is 70% and
the conveyance efficiency is 80% the diversion water requirement is. - ✔✔Answer: 2.5
lps/ha
✔✔A triangular plot of land is to be used as a vegetable garden. The measures of the
plot are AB = 8 meters, BC = 12 meters and AC = 18 meters. Find the measure of angle
B. - ✔✔Answer: 127.2°
✔✔The mass of radium-226 is given by. Its half-life is 1,590 years. A sample radium-
226 has a mass of 1,000 mg. Find the mass after 1,000 years. - ✔✔Answer: 65 mg
✔✔The selling price P of an item is 100 - 0.02x pesos, where x is the number of items
produced per day. If the cost C of producing and selling x items is 40x + 15,000, pesos
per day, how many items should be produced and sold every day in order to maximize
the profit? - ✔✔Answer: 1, 500
✔✔A ladder 10 feet long rests against a vertical wall. If the bottom of the ladder slides
away from the wall at a rate of 1 ft/sec, how fast is the top of the ladder sliding down the
wall when the bottom of the ladder is 6 feet from the wall? - ✔✔Answer: -0.75 ft/sec
✔✔A water tank has the shape of an inverted circular cone with the base radius 2
meters and height 4 meters. If water is being pumped into the tank at a rate of 2
m3/minute, find the rate at which the water level is rising when the water is 3 meters
deep. - ✔✔Answer: 0.28 m/min
✔✔Size up the nozzle for a sprinkler irrigation system given the following: application
rate 12 mm/hr operating pressure 500 kPa, irrigated area 250 m2, discharge coefficient
0.80 - ✔✔Answer: 6.5 mm
