Answer:
A.The positive z-direction
Explanation:
We are given that
Linear charge density of long line which is located on the x-axis=
Linear charge density of another long line which is located on the y-axis=
We have to find the direction of electric field at z=a on the positive z-axis if
and
are positive.
The direction of electric field at z=a on the positive z-axis is positive z-direction .
Because
and
are positive and the electric field is applied away from the positive charge.
Hence, option A is true.
A.The positive z-direction
I assume the block plows into the bank of sand with a velocity of 6 m/s and comes to a stop in 2 s.
Answer:
Explanation:
Given that
Mass , m = 25 kg
We know that when body is in rest condition then static friction force act on the body and when body is in motion the kinetic friction force act on the body .That is why these two forces are given as follows
Static friction force ,fs= 165 N
Kinetic friction force ,fk = 127 N
If the body is moving with constant velocity ,it means that acceleration of that body is zero and all the forces are balanced.
Lets take coefficient of kinetic friction = μk
The kinetic friction is given as follows
fk = μk m g
Now by putting the values
127 = μk x 25 x 9.81


Therefore the value of coefficient of kinetic friction will be 0.51
Answer:
1. Luminosity
2.Apparent brightness
Explanation:
There are two factors on which brightness of star appear to be in the sky
The two factors are
1. Luminosity
2.Apparent brightness
1.Luminosity :It is defined as the total energy emitted by the object in a given time.Luminosity vary with the distance of observer from the star.Luminosity is a intrinsic property which depends on the fundamental chemical composition and structure of the material.Luminosity is depends on the size of star.Lager the star luminosity will be more.
2.Apparent brightness: It is defined as how bright a star appears from an observer on the earth and the amount of starlight reaching the earth.if the distance is large then the brightness decreases.When the distance of star from us small then the brightness of star increases.Distance is inversely proportional to brightness of the star.
Answer:
a)At the mean position
b)At the extremes positions
Explanation:
Given that mass is having oscillation motion.
We know that
1. At the mean position -The velocity of the mass is maximum and the acceleration of the mass is minimum.The net force on the mass will be zero.
2. At the extreme position-The velocity of the mass is minimum and the acceleration of the mass is maximum.The net force on the mass will not be zero.
Therefore
a)At the mean position
b)At the extremes positions