PLEASE HELP ME WITH THIS IF UR GOOD AT PHYSICS!!! 100 POINTS!!!!
2 answers:
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<h2>Hello!</h2>
The answer is C. The television uses 6,588,000 J less than the lamp.
<h2>Why?</h2>First, we must know that 1 Wh( Watt consumed in 1 hour) = 3600 J
Wh is the unit that express the energy amount of consumed in 60 minutes/ 1 hour.
So,
From the enunciate information we can calculate the energy consumed by the lamp and the television.
For the lamp, we have that it left on for 24 hours and it has a power of 120
For the television, we have that it left on for 3 hours and it has a power of 350W
Calculating the energy consumed (Wh) we have:
and converting it to Joule, we have:
Doing the same for the television, we have:
and converting it to Joule, we have:
Finally, we have
:
Then having calculated both consume, we have that the television uses 6,588,000 J less than the lamp.
Answer:
a) W = - 6.825 J, b) θ = 1.72 revolution
Explanation:
a) In this exercise the work of the friction force is negative and is equal to the variation of the kinetic energy of the particle
W = ΔK
W = K_f - K₀
W = ½ m v_f² - ½ m v₀²
W = ½ 0.325 (5.5² - 8.5²)
W = - 6.825 J
b) find us the coefficient of friction
Let's use Newton's second law
fr = μ N
y-axis (vertical) N-W = 0
fr = μ W
work is defined by
W = F d
the distance traveled in a revolution is
d₀ = 2π r
W = μ mg d₀ = -6.825
μ =
The total work as the object stops the final velocity is zero v_f = 0
W = 0 - ½ m v₀²
W = - ½ 0.325 8.5²
W = - 11.74 J
μ mg d = -11.74
we subtitle the friction coefficient value
( ) m g d = -11.74
6.825 = 11.74
d = 11.74/6.825 d₀
d = 1.7201 2π 0.400
d = 4.32 m
this is the total distance traveled, the distance and the angle are related
θ = d / r
θ = 4.32 / 0.40
θ = 10.808 rad
we reduce to revolutions
θ = 10.808 rad (1rev / 2π rad)
θ = 1.72 revolution