Explanation:
It is given that,
The acceleration of a particle, 
(negative as the particle is decelerating)
Initial distance, x₁ = 20 m
Initial time, t₁ = 4 s
New distance x₂ = 4 m
Velocity, v = 10 m/s
(A) Calculating initial distance using second equation of motion as :
u = 21 m/s
When velocity of the particle is zero, time taken is t (say). Using first equation of motion as :
t = 2.62 seconds
So, the velocity of the particle is zero at t = 2.62 seconds.
(B) Velocity at t = 11 s
v = 13 m/s
Total distance covered at t = 11 s. The overall path travelled by the particle during its entire journey is called total distance covered.
d = 132.48 m
So, the distance travelled by the particle at t = 11 seconds is 132.48 meters.
That depends on a few things that you haven't told us about the setup.
So I'm going to assume one of them, and then give you the answer
in terms of another one:
-- Assume a Class-I lever . . . the fulcrum is between the load and the effort.
-- Then the effort needed to lift the load is
(the weight of the load) x (13 / the distance between the fulcrum and the effort)
The two factors that increase the size of a population are natality, which is the number of individuals that are added to the population over a period of time due to reproduction, and immigration, which is the migration of an individual into a place.
In an atom of hydrogen the orbit radius is given by the formula:
r = n² · α₀
where:
n = number of orbit = 15
α₀ = Bohr radius (innermost radius) = 0.529 Â
Since d = 2 · r, we can write:
d = n² · d₀
= 15² · 1.06
= 238.5 Â
Hence, the <span>diameter of the fifteenth orbit of the hydrogen atom is 238.5 </span>Â.
