Answer:
To save the unnecessary bills and carbon emissions.
Explanation:
Energy efficiency is important to society in the following ways:
1. It saves the unnecessary bills as buildings who are using energy efficiently have less demands.
2. Saving energy for the future generations as we know low demand would save the sources.
3. Energy efficiency is also important to society in environmental ways at efficient energy means low carbon emissions.
In the question it is already given that the football player is 80 kg.
Then the mass of the football player = 80 kg
Velocity at which the football player is running = 8 m/s
<span>Kinetic Energy = 0.5 • mass • square of velocity
Now we have to put the known data in this equation to find the actual velocity of the footballer.
</span> <span></span>So
Kinetic Energy of the footballer = 0.5 * 80 * (8 * 8)
= 0.5 * 80 * 64
= 2560
So the Kinetic energy of the footballer is 2560 joules
Answer:
d=1.07m
Explanation:
Calculate Initial Kinetic Energy:
KE = 1/2*m*v^2
KE= 0.5*(10.3kg)*(1.64m/s)^2 = 13.85J
Calculate work overcoming friction:
W = F*d = mu*m*g*d
W = (0.128)*(10.3kg)*9.80m/s^2)*d
W = 12.92*d
Equate the two since all of the kinetic energy is used up in working against friction:
W = KE
12.92d = 13.851J
Solve for d:
d= (13.851J)/(12.92) = 1.07 m
The percentage of mechanical energy of the oscillator lost in each cycle is 5.91 %.
The formula for mechanical energy in an oscillator is given by
E = 1/2 kA²
It is the sum of elastic potential energy and kinetic energy.
Amplitude is nothing but the maximum displacement moved by a point on vibrating body.
It is given that the amplitude A decreases by 3%, then
(E₂ - E₁) / E₁ = [1/2 k (A₂²- A₁²)] /(1/2 k A₁²) = (A₂²- A₁²)/ A₁² = (97² - 100²)/ 100²
⇒ 5.91% of the mechanical energy is lost in each cycle.
To know more about mechanical energy:
brainly.com/question/4285515
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