Solar- the sun is not always shining, for example at night you can't get any energy from the sun
Wind-it's not always windy
Water- there can be drought
Really the main issue of all three of these is that they are not always available
Answer:
MgO.
Explanation:
charges of both satisfy one another (balanced) -- producing a compound MgO.
Answer:
THE HEAT NEEDED TO CHANGE 3KG OF WATER FROM 10 C TO 80 C IS 877.8kJ OR 877,800 J.
Explanation:
Mass = 3.0 kg = 3 * 1000 = 3000 g
Initial temperature = 10 C
Final temperature = 80 C
Change in temperature = 80 - 10 = 70 C
Specific heat of water = 4.18 J/g C
Heat needed = unknown
Heat is the amount of energy in joules needed to change a gram of water by 1 C.
Heat = mass * specific heat * change in temperature
Heat = 3000 g * 4.18 J/g C * 70 C
Heat = 877 800 Joules
Heat = 877.8 kJ.
The heat needed to change 3 kg mass of water from 10 C to 80 C is 877,800 J or 877.8 kJ.
Answer:
19.6 J
Step-by-step explanation:
Before the ball is dropped, it has a <em>potential energy
</em>
PE = mgh
PE = 0.2 × 10 × 9.8
PE = 19.6 J
Just before the ball hits the ground, the potential energy has been converted into kinetic (<em>mechanical</em>) energy.
KE = 19.6 J
Answer: <em>Newton's first law</em>
Explanation: <em>The idea that objects only change their velocity due to a force is encapsulated in Newton's first law. Newton's first law: An object at rest remains at rest, or if in motion, remains in motion at a constant velocity unless acted on by a net external force.</em>
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