Answer:
4th answer
Explanation:
The gradient of a distance-time graph gives the speed.
gradient = distance / time = speed
Here, the gradient is a constant till 30s. So it has travelled at a constant speed. It means it had not accelarated till 30s. and has stopped moving at 30s.
Dont really understand what youre asking but switches can be used to turn things on and off.
Out of the 3 types of heat transfer, this scenario would be most likely to be an example of convection.
Convection is where the transferring of heat is resulted through the movements of fluid, but in this case it is air. What happens is that when a part of the whole mass of air is heated, the hotter air rises and the cooler air descends and takes place of the hotter air before it was heated. Then, the cooler air becomes hotter and the hotter air before becomes the cooler air of both, which then results to the repeat of the exchange of places. This creates a motion until the whole mass has achieved mutual temperature, the heat source has stopped or extinguished, or there is a shift of temperature.
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
