Answer:
By the use of slow motion camera.
Explanation:
Visually, it is very hard to differentiate between an ac and dc power supply. But Since, we that In Ac supply polarity changes 100 times in a second ( because frequency of ac supply is 50 Hz generally). Whereas, Dc gives a steady power supply. So, in slow motion camera we can easily capture the flickering light tubes which won't happen in case of dc supply.
Part a.
u = 0, the initial velocity
v = 60 mi/h, the final velocity
a = 2.35 m/s², the acceleration.
Note that
1 m = 1609.34 m.
Therefore
v = (60 mi/h)*(1609.34 m/mi)*(1/3600 h/s) = 26.822 m/s
Use the formula
v = u + at
(26.822 m/s) = (2.35 m/s²)*(t s)
t = 26.822/2.35 = 11.4 s
Answer: 11.4 s
Part b.
We already determined that v = 60 mi/h = 26.822 m/s.
t = 0.6 s
Therefore
(26.822 m/s) = (a m/s²)*(0.6 s)
a = 26.822/0.6 = 44.7 m/s²
Answer: 44.7 m/s²
This question is incomplete because the options are missing; here is the complete question:
A runner starts at point A, runs around a 1-mile track, and finishes the run back at point A. Which of the following statements is true?
A. The runner's displacement is 1 mile.
B. The runner's displacement is zero.
C. The distance the runner covered is zero.
D. The runner's speed was zero.
The answer to this question is B. The runner's displacement is zero
Explanation:
Displacement always implies a change of position; this means an object or individual moves from point A to point B, and therefore the original position is different from the final position. Additionally, in displacement, other related factors such as the total distance the body moved and the direction of movement. In the case presented, it can be concluded there was no displacement or the displacement is zero because even when the runner moved and ran two miles, he returned to the initial position, and without a change in the position, there is no displacement.
Answer:

Explanation:
= Change in frequency = 2.1 Hz
= Frequency of source of sound = 440 Hz
= Maximum of the microphone
= Speed of sound = 343 m/s
= Time period = 2 s
We have the relation

Amplitude is given by

The amplitude of the simple harmonic motion is
.
Explanation:
The speed of light is 300,000,000 m/s. There are 8 zeros, so in scientific notation, the speed is 3×10⁸ m/s.