first we make a U turn and travel towards home in t = 20 s
so the distance of home from initial position is
Now after picking up the book we travel back with speed 20 m/s
so again after t = 20 s the displacement is given as
so the net displacement is given as
so it will be displaced by total displacement 200 m
Answer:
V=20cm/s
Explanation:
The average speed is the distance total divided the time total:
First stage:
T1=5s
But, 
(decelerates to rest)
then: 
on the other hand:
X1=75cm
Second stage:
T2=5s
X2=125cm
Finally:
X=X1+X2=200cm
T=T1+T2=10s
V=X/T=20cm/s
For this, we need the formula:
V = k q / r
where k is the Coulombs law constant = 9 x 10^9 N
q is the charge of the hydrogen nucleus (proton) = <span>1.6 x 10^-19 C</span>
r is the distance
Simply plug in the values and solve for V
Answer:
1 ) Electrons are less massive than than atomic nuclei.
Explanation:
A positively charged body tends to attract negatively charged particle and repel positively charged particle. Neutral body consists of atoms which contain both positively charged particles ( electrons ) and negatively charged particles ( protons ). Electrons are small and light in weight . Both electrons and protons experience equal and opposite force by an external charged body but shift in electron is more because of their being comparatively lighter. So the body gets polarized due to uneven distribution of charge. This results into body getting attracted through the process of induction.
To
solve this problem, we assume that the wavelength of the light in air is 500
nanometers.
For this case we
only need the refractive index of the polystyrene. For an antireflective
coating, we need a quarter of wave thickness at the wavelength in the air. Which
means that the antireflective coating needs to be as thick as 1/4 of the
wavelength, divided by the coating’s refractive index. This is expressed
mathematically in the form:
x = λ / (4 * n)
where,
x = thickness
λ = wavelength
of light
n = index of
refraction of polystyrene
Substituting:
x = 500 nm / (4
* 1.49)
x = 500 nm / 5.96
x = 83.90 nm
