Explanation:
everything can be found in the picture
Here observer is moving along with an electrical charge
now magnetic field on a moving charge is given by equation

electrical force on a moving charge is given by formula

so here we can say when observer is moving with the charge it will have two forces on it
1. magnetic force due to existing magnetic field
2. electric force due to electric field
so here he must have to experience both type of field presence
So here correct answer must be
<em>C- electric and magnetic fields </em>
Answer:
The new intensity decreases by a factor of 16.
Explanation:
The intensity of sound wave is given by :

P is power
A is area

or
, r is distance from the source
If the distance from the source is increased by a factor of 4, r' = 4r
So,

So, the new intensity decreases by a factor of 16.
.05 cm far must the lens be moved to change the focus of the camera from a person 25 m away to one that is 4.0 m away
The focal length of a thin lens in air is the separation between its major foci, also known as focal points, and its center. The focal length is the distance at which a beam of collimated light will be concentrated to a single spot for a converging lens (for instance, a convex lens).
If v is the image distance in the first scenario
1 / v - 1 / -25 = 1 / .05
1 / v = 1 / .05 - 1 / 25
= 20 - .04 = 19.96
v = .0501 m = 5.01 cm
The second instance
u = 4 ,
1 / v - 1 / - 4 = 1 / .05
1 / v = 20 - 1 / 4 = 19.75
v = .0506 = 5.06 cm
Therefore, the lens must be advanced by 5.06 - 5.01 =.05 cm.
Learn more about lens here brainly.com/question/17086993
#SPJ4.
Using the graph, which describes how Henry ran the 100m race;
a) It takes Henry 20seconds to run 100m
b) Henry's average speed over the race is; 5m/s.
According to the linear graph which describes the distance ran by Henry during the 100m race as a function of time.
a) Since the distance from start ran by Henry is plotted on the vertical axis, and the time is plotted on the horizontal axis;
To determine how long it took Henry to run 100m; The point corresponding to 100m is traced downward from the line of the graph and we find out that;
It takes Henry 20seconds to run 100m
b) Henry's average speed over the race is simply;
The slope of the distance-time graph.
Therefore,
- Average speed = (100-0)/(20-0)
Therefore, Henry's average speed over the race is; 5m/s.
Read more:
brainly.com/question/22125199