Answer:
Its initial position was 471 m.
Explanation:
We have,
Final position of the object is 327 m
Displacement of the object is -144 m
It is required to find its initial position. The difference of final and initial position is equal to the displacement of the object. So,

So, its initial position was 471 m.
Answer:
Radius between electron and proton
Explanation:
The motion of the electron is carried out in the orbit due to the balancing of the electrostatic force between the proton and the electron and the centripetal force acting on the electron.
The electrostatic force is given as = 
Where,
k = coulomb's law constant (9×10⁹ N-m²/C²)
q₁ and q₂ = charges = 1.6 × 10⁻¹⁹ C
r = radius between the proton and the electron
Also,
Centripetal force on the moving electron is given as:
=
where,
= mass of the electron (9.1 ×10⁻³¹ kg)
V = velocity of the moving electron (given: 6.1 ×10⁵ m/s)
Now equating both the formulas, we have
= 
⇒
substituting the values in the above equation we get,

⇒
Answer:

45.03681 m/s²
Explanation:
= Buoyant force
W = Weight of the balloon
= Density of air = 1.23 kg/m³
= Density of balloon = 0.22 kg/m³
= Volume of air
= Volume of balloon


g = Acceleration due to gravity = 9.81 m/s²
The net force acting on the balloon is

The equation is 

The acceleration of the balloon is 45.03681 m/s²
The process that most directly helps create soil from rocks is Weathering.
I will assume here that the well is sufficiently short so that the time the sound takes to come from the bottom of the well to our ear is negligible.
Since the pebble moves by uniformly accelerated motion, the distance it covers is given by

where

is the gravitational acceleration

is the time the pebble takes to reach the bottom of the well
Therefore, the depth of the well is

and the correct answer is B.