i think the answer is D.
heating surface water causes it to evaporate and enter the air as a gas.
It would be, 1.000. Hope that helps :)
I think the correct answer from the choices listed above is option B. When calculating the power bill, power companies use kilowatt-hours. This unit is a derived unit of energy equal to 3.6 MJ. If energy is being transmitted or used at a constant rate (power) over a period of time, the total energy in kilowatt-hours is the product of the power in kilowatts and the time.
Answer:
54 Kobo
Explanation:
Units of <u>electricity</u> are measured in kilowatt hours (kWh).
Given information:
- 900 watt electric iron
- Appliance usage = 4 hours a week for 5 weeks
- Unit cost of electricity = 3 Kobo per kWh
<h3><u>Step 1</u></h3>
Convert the wattage of the electric iron from watts to kilowatts.
1000 watts (W) = 1 kilowatt (kW)
⇒ 900 watts = 1 ÷ 1000 = 0.9 kilowatts
This means that the power consumption of the electric iron is 0.9 kW per hour of use.
<h3><u>Step 2</u></h3>
Total hours spent pressing clothes:
= 4 hours per week for 5 weeks
= 4 × 5
= 20 hours
<u>Total power consumption</u>:
= number of kW × number of hours
= 0.9 × 20
= 18 kWh
<h3><u>Step 3</u></h3>
To find the <u>total cost</u>, multiply the total kWh by the cost per kWh:
⇒ Cost = 18 × 3 = 54 Kobo
Answer:
22.11 m / s
Explanation:
The falcon catches the prey from behind means both are flying in the same direction ( suppose towards the left )
initial velocity of falcon = 28 cos 35 i - 28 sin 35 j
( falcon was flying in south east direction making 35 degree from the east )
momentum = .9 ( 28 cos 35 i - 28 sin 35 j )
= 20.64 i - 14.45 j
initial velocity of pigeon
= 7 i
initial momentum = .325 x 7i
= 2.275 i
If final velocity of composite mass of falcon and pigeon be V
Applying law of conservation of momentum
( .9 + .325) V = 20.64 i - 14.45 j +2.275 i
V = ( 22.915 i - 14.45 j ) / 1.225
= 18.70 i - 11.8 j
magnitude of V
= √ [ (18.7 )² + ( 11.8 )²]
= 22.11 m / s