Answer:
The correct one is (III)
Explanation: Limited and uncertain supply and the increasing requirements for pollution control are raising the cost of using fossil fuels.
This is because fossil fuels emit green house gases that are causing global warming. As a result more awareness have been drawn towards the harmful use of fossil fuels, and international bodies are starting to form regulations on the use of fossil fuels. These above reasons has made fossil fuels though abundant, very expensive to use.
This make the usage of greener sources of energy like solar energy desirable. The only challenge solar is facing is on the area of efficiency, but scientists are constantly researching to make it more efficient.
Weight is mass times gravitational acceleration. Without a specific location, Earths average gravitational acceleration is 9.807.
So .5x9.8.07= weight
The answer is 4.9035 newtons
Answer:
Explanation:
a) The second arm measures the minutes. The difference between 9:17:30 and 9:15:00 is 2 minutes 30 seconds. This means the second arm would have revolved 2.5 times.
The circumference = 2πr= 2π(13.5 cm) = 84.823 cm
Distance = 2.5 × 84.823 cm = 212 cm = 2.12 m
b) Displacement of an object is the shortest distance between the initial and final point. Since the second arm revolves 2 and half times, we use only the half times (a semicircle)
Displacement for semicircle = 2r = 2(13.5) = 27 cm
c) Average speed = distance / time
time = 2 minutes 30 seconds = 150 seconds
Average speed = 212 cm / 150 s = 1.41 cm/s
d) Average velocity = displacement / time = 27 cm / 150 s = 0.18 cm/s
e) number of revolutions = 100 m / circumference = 100 m / 0.848 m = 117.92
but 1 revolution = 1 minute
117.92 revolution = 117 minutes 55 seconds = 1 hour 57 minutes 55 seconds
Hence the time would be: 11:12:55
