Answer:
Given:
Mass of the polar bear (m) = 6.8 kg
Speed of the polar bear (v) = 5.0 m/s
To Find:
Kinetic energy of the polar bear (KE)
Explanation:
Formula:
Substituting values of m & v in the equation:
Kinetic energy of the polar bear (KE) = 23002.1 J
That's a great idea ! A wind turbine (windmill) or solar panels
on the roof of every WalMart, but don't stop there. Let K-Mart,
Target, Sears, Macy's, 7-11, McDonald's, and Subway in on it too.
In fact, why not place them on the roof of every house and
apartment building too ?
Just one question: Who's going to pay for them ?
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The biggest single year-round residential use of energy in the
USA is to heat up and keep a ready supply of hot water. So the
single biggest residential use of energy could be eliminated with
a simple solar water heater on the roof of every house. From my
own personal observation, I know that Israel is there now, but here
in the USA, it's apparently not worth the time, effort, or expense ! ? !
Answer: condensation process is exothermic. The correct option is IV.
Explanation: Exothermic reaction is a chemical reaction in which heat is released to the surrounding environment.
condensation is defined as a process by which a medium changes from gaseous phase into liquid phase. Using water molecules to illustrate, to transform water molecules to gaseous phase it requires the heat of vaporization to be overcomed. This same hear of vaporization needs to be given off when changing back to liquid phase.
Answer:
1716.75 J
Explanation:
<u>Step </u><u>1</u><u>:</u> First check what we are provided with. As per given question we have:
mass (m) = 70 kg, height (h) = 2.5 m and acceleration due to gravity (g) = 9.81 m/s².
<u>Step</u><u> </u><u>2</u><u>:</u> Check what we are asked to find out.
Work done = Change in Potential energy
The stuff required to solve this question is potential energy. Using the formula: P = mgh. Where P is Potential energy, m is mass, g is acceleration due to gravity and h is height.
<u>Step</u><u> </u><u>3</u><u>:</u> Substitute the known values in the above formula.
→ P = 70 × 2.5 × 9.81
→ P = 1716.75 J
Hence, the work done against the force of gravity is 1716.75 J.