Answer: b. Electrons move from glass to silk
Explanation:
When the glass rod is rub over against the silk, the glass loses the electrons due to the physical contact with the silk and the friction so produced. The surface of the glass becomes positively charged and the surface of the silk becomes negatively charged. As the surface of the glass loses electrons which are accepted by the silk surface.
If a force always acts perpendicular to an object's direction of motion, that force cannot change the object's kinetic energy. It is a true statement .
Kinetic energy is the energy that an object possesses due to its motion. It is basically the energy of mass in motion. Kinetic energy can never be negative and it is a scalar quantity i.e. it provides only the magnitude and not the direction.
According to law of conservation of mechanical energy change in potential energy is equal and opposite to the change in the kinetic energy.
According to the principle of conservation of mechanical energy, The total mechanical energy of a system is conserved i.e., the energy can neither be created nor be destroyed; it can only be internally converted from one form to another if the forces doing work on the system are conservative in nature.
since, potential energy is stored in the form of work done
Work done = Fs cos (theta)
If force always acts perpendicular to an object's direction of motion
theta = 90 °
cos (90 ) = 0
Work done = 0
since , there is no work done , hence kinetic energy will not change
To learn more about kinetic energy here
brainly.com/question/12669551
#SPJ4
Answer:
a) 
b) 
Explanation:
Given;
- depth of the water-tank,
- length of the pipe,
- inclination of the pipe from the horizontal,
a)
Now the effective vertical height of the water column from the free surface of the water to the bottom of the pipe at house:
Now the pressure due to effective water head:
where:
density of the liquid, here water
acceleration due to gravity
height of the liquid column
b)
Now the height of water corresponding to this pressure will be the same as the effective water head by the law of conservation of energy.
Answer:
Explanation:
For third normal mode of vibration
l = 
, λ is wavelength , l is length of string .
.4 =
λ = .267 m
velocity = 
T is tension and m is mass unit length
m = .5 x 10⁻³ / 40 x 10⁻²
= .00125 kg / m
Putting the values
velocity = 
= 253 m /s
frequency
= velocity / λ
= 253 / .267
= 947.5 Hz .
Answer: (c) Context Effect
Explanation: Context Effect is an aspect of cognitive psychology which describes how environmental factors afects a person's perception of stimuli. It is known to occur at all scales at which words may be viewed. It is supported by constructive perception, the effect of a context perception is known to be part of a top-down design, the view of the moon through a narrow tube which has affected the perception of the viewer who now see the moon as shrinking in size is a context perception.
