The first question would be A
The second would be either A or D
Answer
given,
radius of the circular orbit, r = 0.53 x 10⁻¹⁰ m
mass of electron, M = 9.11 x 10⁻³¹ Kg
charge of electron, q₁ = 1.6 x 10⁻¹⁹ C
q₂ = 1.6 x 10⁻¹⁹ C
we know, force between two charges


F = 8.20 x 10⁻⁸ N
b) using newton's second law
F = m a
m a = 8.20 x 10⁻⁸

a = 9 x 10²² m/s²
c) speed of the electron


v² = 4.77 x 10¹²
v = 2.18 x 10⁶ m/s
d) the period of the circular motion.



T = 1.53 x 10⁻¹⁶ s
Answer:
(2/3) times height collision occur
Explanation:
for ball A
from the kinematic equation
the distance of ball A is

= velocity ( time ) = distance
since ball is at height, the above equation changes as

for ball B

the condition of collision is
xA = xB
(given)
from the kinematic equation
the speed of the ball A is

since initial speed of the ball A is zero
, so

the speed of the ball B is

since




since 






so, (2/3) times height collision occur