<span>You are given two cars, one in front of the other, that are traveling down the highway at 25 m/s. You are also given a frequency of 500 Hz of the car travelling behind it. You are asked what is the frequency heard by the driver of the lead car. This problem can be solved using the Doppler effect
sound frequency heard by the lead car = [(speed of sound + lead car velocity)/( speed of sound + behind car velocity)] * (sound of frequency of the behind car)
</span>sound frequency heard by the lead car = [(340 m/s + 25 m/s)/(340 m/s - 25 m/s)] * (500 Hz)
sound frequency heard by the lead car = 579 Hz
Answer:
<em>Time period of pendulum is 2.02 s.</em>
Explanation:
A <em>simple pendulum</em> is a device which consists of mass m hanging from the string of length L attached to the some point.When displaced and released its swings back and forth with periodic motion.
The time period of pendulum is defined as time taken by the pendulum to complete one full oscillation . it is denoted by T.
By <em>Huygens law of period of pendulum</em>,
T = 2π
eqn 1
where L is the length of pendulum,
g is acceleration due to gravity
<em>Period of pendulum is independent of the mass of pendulum,</em>
<em />
Substituting values in eqn 1
T = 2π 
T = 2.02 s
<em>Time period of pendulum is 2.02 s.</em>
Comes in pairs
Just like in Newton’s 3rd law, there is always an equal and opposite force