Answer:
W=16.58J
Explanation:
initial information we have
work: 
stretched distance: 
from this, we can find the value of the constant of the spring k, with the equation for work in a spring:

substituting known values:

and clearing for k:

and now we want to know how much work is done when we stretch the spring a distance of 6.5cm from equilibrium, so now x is:

and using the same formula for work, with the value of k that we just found:


These days, scientists all over the world use a standard system of measurements. It's the SI or metric system.
What about scientists in the United States, Liberia, and Burma ?
These three countries are the only ones in the world that haven't
adopted the metric system. What do THEY do ?
Easy. When scientists in those countries are off work, they use the
inches, yards, feet, quarts, miles and gallons that everybody around
them is using. But when they go to work, they use the same metric
system that everyone else in the world is using.
Answer:
A. the total net force is 14
B. the total net force is 15
Explanation:
Answer:
Explanation:
In case of oil slick a thin layer of oil is formed on water . This thin layer creates a rainbow of colour . The phenomenon is due to interference of light waves , one reflected from the upper surface of oil and the other reflected from the lower surface of the oil.
For formation of bright colour
2 μ t = ( 2n + 1 ) λ / 2
μ is refractive index of oil , t is thickness of oil layer λ is wave length of light falling on the layer .
given μ = 1.2 , λ = 750 x 10⁻⁹ ,
2 x 1.2 t = ( 2n + 1 ) 750 x 10⁻⁹ / 2
For minimum thickness n = 0
2.4 t = 375 x 10⁻⁹
t = 156.25 n m
B ) If the refractive index of layer of medium below oil is less than that of oil , the condition of formation of colour changes
The new condition is
2 μ t = n λ
2 x 1.5 t = 750 nm , n = 1 for minimum wavelength .
t = 250 nm
C ) Light mostly transmitted means dark spot is formed at that point .
For that to be observed from water side , the condition is
2 μ t = ( 2n + 1 ) λ / 2
λ = 4μ t / ( 2n + 1 )
For maximum wavelength n = 0
λ = 4μ t
= 4 x 1.5 x 200 nm
= 1200 nm .