Answer:
(D) 0.99 cm
Explanation:
Given that the radius of curvature of the mirror is 25 cm.
And another car is following which is behind the mirror of 20 m.
Focal length is half of the radius of curvature and it is negative for convex lens.
Now the mirror formula.
So,
Now
Magnification is,
So,
So, Height of the image
Therefore, the image height is 0.99 cm.
Answer:
Explanation:
We define the linear density of charge as:
Where L is the rod's length, in this case the semicircle's length L = πr
The potential created at the center by an differential element of charge is:
where k is the coulomb's constant
r is the distance from dq to center of the circle
Thus.
Potential at the center of the semicircle
Answer:
9.34 N
Explanation:
First of all, we can calculate the speed of the wave in the string. This is given by the wave equation:
where
f is the frequency of the wave
is the wavelength
For the waves in this string we have:
, since it completes 625 cycles per second
is the wavelength
So the speed of the wave is
The speed of the waves in a string is related to the tension in the string by
(1)
where
T is the tension in the string
is the linear density
In this problem:
is the mass of the string
L = 0.75 m is the its length
Solving the equation (1) for T, we find the tension: