Conservation and Rain Water Tank. Through conservation, they can save water in their own houses by lessening the use of water in an unimportant purpose; they can turn of the faucet when it is not used; they can use their laundry water to clean the bathroom and there are more. Through Rain Water Tank, they can create this structure in order to collect rain water and store it in the tank then use it afterwards such as in watering the plants.
Answer:
The boat won't be able to move if the oars were out and there was no thruster. If there was a flow of the water then yes there would be a moving boat.
Answer:
The torque is 0.31 Nm.
Explanation:
Electrical energy, E = 8400 J
time, t = 1 min
Angular speed, w = 2900 rpm = 303.53 rad/s
efficiency = 2/3 of input power
The toque is given by

Answer:
0.182 m/s
Explanation:
m1 = 30,000 kg, m2 = 110,000 kg, u1 = 0.85 m/s
let the velocity of loaded freight car is v
Use the conservation of momentum
m1 x u1 + m2 x 0 = (m1 + m2) x v
30,000 x 0.85 = (30,000 + 110,000) x v
v = 0.182 m/s