2. Harry is pushing a car down a level road at 2.0 m/s with a force of 243 N. The total force
1 answer:
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Answer and explanation:
The efficiency of the LED bulb is 20% while The efficiency of the Inc bulb is 1%.
The lightbulb efficiency can be defined as the quotient between the amount of usable light and the amount of electrical power output. For the efficiency of the CFL Bulb:
Therefore:
Answer:
v = 54.2 m / s
Explanation:
Let's use energy conservation for this problem.
Starting point Higher
Em₀ = U = m g h
Final point. Lower
= K = ½ m v²
Em₀ = Em_{f}
m g h = ½ m v²
v² = 2gh
v = √ 2gh
Let's calculate
v = √ (2 9.8 150)
v = 54.2 m / s
To solve this problem we will apply the concepts related to the Doppler effect. The Doppler effect is the change in the perceived frequency of any wave movement when the emitter, or focus of waves, and the receiver, or observer, move relative to each other. Mathematically it can be described as
Here,
=frequency received by detector
=frequency of wave emitted by source
=velocity of detector
=velocity of source
v=velocity of sound wave
Replacing we have that,
Therefore the frequencty that will hear the passengers is 422Hz