A 1.00-kilogram ball is dropped from the top of a building. just before striking the ground, the ball's speed is 12.0 meters per
1 answer:
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Answer:
amount of energy = 4730.4 kWh/yr
amount of money = 520.34 per year
payback period = 0.188 year
Explanation:
given data
light fixtures = 6
lamp = 4
power = 60 W
average use = 3 h a day
price of electricity = $0.11/kWh
to find out
the amount of energy and money that will be saved and simple payback period if the purchase price of the sensor is $32 and it takes 1 h to install it at a cost of $66
solution
we find energy saving by difference in time the light were
ΔE = no of fixture × number of lamp × power of each lamp × Δt
ΔE is amount of energy save and Δt is time difference
so
ΔE = 6 × 4 × 365 ( 12 - 9 )
ΔE = 4730.4 kWh/yr
and
money saving find out by energy saving and unit cost that i s
ΔM = ΔE × Munit
ΔM = 4730.4 × 0.11
ΔM = 520.34 per year
and
payback period is calculate as
payback period =
payback period =
payback period = 0.188 year
A) The mass of the continent is
B) The kinetic energy is 2016 J
C) The speed of the jogger should be 7.1 m/s
Explanation:
A)
The mass of the continent can be calculated as
where
is its density
V is its volume
We have to calculate its volume. We know that the continent is represented as a slab of side 5900 km (so its surface is 5900 x 5900, assuming it is a square) and depth of 26 km, so its volume is:
So, the mass of the continent is
B)
The kinetic energy of a body is given by
where
m is the mass of the body
v is its speed
For the continent, we have:
is the mass
is the speed
We have to convert the speed into SI units. we have:
1 cm = 0.01 m
So, the speed is
Therefore, the kinetic energy is
C)
Again, the kinetic energy of an object is
For the jogger in this problem, his mass is
m = 80 kg
And we want its kinetic energy to be equal to that of the continent, so
K = 2016 J
Re-arranging the equation for v, we find what speed the jogger needs to have this kinetic energy:
Learn more about kinetic energy here:
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