Answer:
Because it makes our lives easier.
Explanation:
When we talk about nonrenewable resources, it's usually fossil fuels that derive from crude oil. After dividing the useless crude oil into different fractions, you get gases, petrol, kerosene, diesel, fuel oil and bitumen. Each fraction has their own unique purpose i.e: petrol as a fuel for cars.
We use plastic bags for our ease. They consist of a long chain of 'alkenes' that's called poly(ethylene). The long chain was made by smaller molecules from crude oil.
When these bags are burnt for disposal, they release toxic fumes. One being carbon monoxide.
Answer:
Explanation:
given,
Light wave wavelength in Air, λ_(vac) = 670 nm
wavelength in transparent solid, λ= 420 nm
Refractive index of the solid


n = 1.6
a) speed of light in the solid


v = 0.625 c
b) light's frequency in the solid

frequency of light remain same when light move from one medium to another.
f is the frequency of light

f = 4.47 x 10⁻¹⁴ Hz
the light's frequency in the solid is equal to 4.47 x 10⁻¹⁴ Hz
Answer:
3.28 degree
Explanation:
We are given that
Distance between the ruled lines on a diffraction grating, d=1900nm=
Where 


We have to find the angular width of the gap between the first order spectrum and the second order spectrum.
We know that

Using the formula
m=1


Now, m=2





Hence, the angular width of the gap between the first order spectrum and the second order spectrum=3.28 degree
As per Kepler's third law we know that

now here we know that
= year of Neptune
= year of Earth
= distance of Neptune from Sun
= Distance of Earth from Sun
so now we will have



so length of year of Neptune is 164.3 years
Answer:
a=g(sinθ-μkcosθ)
Explanation:
In an inclined plane the forces that interact with the object can be seen in the figure. The normal force, the weight w and the decomposition of the force vector of weight can be observed.
wx=m*g*sinθ
wy=m*g*cosθ
As the objects moves down an incline, acceleration in y axis is 0.
Then, by second Newton's Law:
Fy = m*ay
FN - m*g cos θ = 0,
FN=m*g cos θ
In x axis the forces that interacs are the x component of weight and friction force:
Fx = m*ax
mg sen u-FN*μk=m*a
Being friction force, Fr=FN*μk, we replace with its value in below formula:
m*g *sinθ-(m*g*cosθ*μk)=m*a
Then, isolating a:
a=(m*g sinθ-(m*g*cosθ*μk))/m
Solving, we have next equation:
a=g sinθ-(g*cosθ*μk)
Applying distributive property we have:
a=g*(sinθ-μk*cosθ)