Answer:
(a) 1320 W
(b) 480 W
(c) E':E ≈ 11:2
Explanation:
(a) Applying,
P' = VI'................. Equation 1
Where P' = Power of the blow-dryer, V = Voltage, I = current rating of the blow-dryer.
From the question,
Given: V = 120 V, I' = 11 A
Substitute these values into equation 1
P = (120×11)
P = 1320 W
(b) Similarly,
P = VI................... Equation 2
Where P = Power of the vacuum cleaner. I = current rating of the vacuum cleaner.
Also Given: I = 4 A,
Therefore
P = 4(120)
P = 480 W
(c)
E' = P'/t'............. Equation 3
E = P/t................ Equation 4
Where E' = Energy of the blow-dryer, t' = time of use of the blow-dryer, E = Energy of the vacuum cleaner, t = time of use of the vacuum cleaner
From the question,
Given: t' = 15 minutes = (15×60) = 900 seconds, t = 30 minutes = (30×60) = 1800 seconds
Substitute these values into equation 3 and 4
E' = 1320/900
E' = 1.47 J,
E = 480/1800
E = 0.267
Therefore,
E':E = 1.47:0.267
E':E ≈ 11:2
Answer: 47.6 m/s
Explanation: Please see attached for the calculation and formula.
Answer:
0.02
Explanation:
coefficient of kinetic friction = μ
force of friction = Ff
Normal Force = FN, but
FN = -W
Ff = -μFN
so μ = Ff/FN
= 4N/200N
= 0.02.
To solve this problem we will apply the concepts related to the work theorem for which it is defined as the product of Force and distance. In turn, we will use the energy conservation theorem for which the applied work must be equivalent to the total kinetic energy on the body.
The work is defined as
Here,
F = Force
d = Displacement
Replacing with our values we have that
Now by conservation of energy,
Solving for v,
Therefore the correct answer is D.
Explanation:
All the energy in oil, gas, and coal originally came from the sun captured through photosynthesis. In the same way that we burn wood to release energy that trees capture from the sun, we burn fossil fuels to release the energy that ancient plants captured from the sun.
