Answer:
-7.14
Explanation:
According to equation of motion
v = u + at
where
v is the final velocity at any time t
u is the initial velocity
a is the acceleration
and t is the time
___________________________________________
Given
An object is thrown upward it means
its initial velocity is in upward direction
but acceleration due to gravity is in downward direction which will cause to decrease the velocity of object.
Intial velocity u = 31.1 m/s
final velocity v at 4 second we have to find.
t = 4 second
a = g = 9.81 m/s2 (it is acting in opposite direction of motion hence its sign will be negative ).
Thus
a = - 9.81 m/s2
using the above values in v = u + at
v = 32.1 - 9.81*4
v = 32.1 - 39.24
v = -7.14
Thus, correct option is -7.14.
Not sure but i will say D
Answer:
Explanation:
F = 2.12 x 10⁻²⁶ / x²
Work done by electric field of nucleus
W = ∫ Fdx
= ∫2.12 x 10⁻²⁶ / x² dx
= 2.12 x 10⁻²⁶ ( - 1 / x )
= - 2.12 x 10⁻²⁶ ( 1/5 - 1 / 8 x 10⁻¹⁰ )
= - .265 x 10⁻¹⁶ J
1/ 2 x mv² = .5 x 1.67 x 10⁻²⁷ x 9 x 10¹⁰ - .265 x 10⁻¹⁶
= 7.515 x 10⁻¹⁷ - .265 x 10⁻¹⁶
=( .7515 - .265 )x 10⁻¹⁶
= .4865 x 10⁻¹⁶
.5 x 1.67 x 10⁻²⁷ x v² = .4865 x 10⁻¹⁶
v² = .5826 x 10¹¹
v² = 5.826 x 10¹⁰
v = 2.41 x 10⁵ m /s
b )
Let r be the closest distance
Potential at this point
2.12 x 10⁻²⁶ ( 1 / r )
Kinetic energy
= 0
Total energy = 2.12 x 10⁻²⁶ ( 1 / r )
Total energy at 5 m
= .5 x 1.67 x 10⁻²⁷ x 9 x 10¹⁰ + 0 ( potential energy at 5 m will be negligible as compared with that near the center )
= 7.515 x 10⁻¹⁷ J
So ,
2.12 x 10⁻²⁶ ( 1 / r ) = 7.515 x 10⁻¹⁷
r = 2.12 x 10⁻²⁶ / 7.515 x 10⁻¹⁷
= .282 x 10⁻⁹
= 2.82 x 10⁻¹⁰ m
c ) As electric field is conservative , no dissipation of energy takes place . Hence its speed at 5m on returning back to this point will be same as
3.00 x 10⁵ m /s
An Astronomer who made a list of 100 nebulae and galaxies that could
be mistaken for comets was Charles Messer's.
Charles Messier's was a very famous scientist in the field of Astronomy.
His research in appearance of Great comet filled spark to his passion
of Astronomy. On January 21, 1759 he put his thought of wrong
calculation of Delisle's and he described a faint glow resembling comet
had been seen earlier. Then after, he discovered great comet near
sword of Orion.
There are various tales of Charles Messiers which put him forward
towards his love of Astronomy.
Learn more about comet and Nebulae here:
brainly.com/question/21420531
#SPJ4
Answer:
533.33 nm
Explanation:
Since dsinθ = mλ for each slit, where m = order of slit and λ = wavelength of light. Let m' = 10 th order fringe of the first slit of wavelength of light, λ = 640 nm and m"= 12 th order fringe of the second slight of wavelength of light, λ'.
Since the fringes coincide,
m'λ = m"λ'
λ' = m'λ/m"
= 10 × 640 nm/12
= 6400 nm/12
= 533.33 nm
