Answer:
Q must be placed at 0.53 L
Explanation:
Given data:
q_1 = 4.0 μC , q_2 = 3.0μC
Distance between charge is L
third charge q be placed at distance x cm from q1
The force by charge q_1 due to q is

----1
The force by charge q_2 due to q is

--2
we know that net electric force is equal to zero
F_1 = F_2





x = 0.53 L
Q must be placed at 0.53 L
1) Sleeping with an electronic in charge right next to you.
2) Leaving a charger plugged in all the time especially near liquid substances.
Answer:
M=125 kg
v=1.75 m/s
Explanation:
From the law of linear momentum
P =mv
Case 1 50*V =M* 0.7 equation 1
50*V =(M+50)* 0.5 equation 2
equating 1 and 2
M* 0.7=(m+50)* 0.5
0.2 M= 25
M=125 kg
Putting value of M in equation 1
50*V =125*0.7
V=1.75 m/s
The frequency of the human ear canal is 2.92 kHz.
Explanation:
As the ear canal is like a tube with open at one end, the wavelength of sound passing through this tube will propagate 4 times its length of the tube. So wavelength of the sound wave will be equal to four times the length of the tube. Then the frequency can be easily determined by finding the ratio of velocity of sound to wavelength. As the velocity of sound is given as 339 m/s, then the wavelength of the sound wave propagating through the ear canal is
Wavelength=4*Length of the ear canal
As length of the ear canal is given as 2.9 cm, it should be converted into meter as follows:

Then the frequency is determined as
f=c/λ=339/0.116=2922 Hz=2.92 kHz.
So, the frequency of the human ear canal is 2.92 kHz.
Strange as it may seem, the object would keep moving, in a straight line and at the same speed, until it came near another object. Its momentum and kinetic energy would never change. It might continue like that for a billion years or more.
Have a look at Newton's first law of motion.