Explanation:
It is given that,
The Displacement x of particle moving in one dimension under the action of constant force is related to the time by equation as:
Where,
x is in meters and t is in sec
We know that,
Velocity,
(a) i. t = 2 s
At t = 4 s
(b) Acceleration,
Pu t = 3 s in above equation
So,
Hence, (a) (i) v = 55 m/s (ii) v = 211 m/s and (b) 78 m/s²
Answer:
A. Elements with intermediate numbers of valence electrons are the last chemically stable.
Explanation:
Answer:
B electricity could not be distributed through power lines to people's homes
Answer:
The correct answer is c
Explanation:
In these two different models of movement of the planets
Ptolemy raises the Earth as the center of the solar system
In the Copernicus system, it poses the Sun as the center of the solar system.
Copernicu's system was accepted for giving a simpler and more complete explanation of the problem
The correct answer is c
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
