Answer:
option C
Explanation:
given,
Q = +3.2 x 10⁻¹⁹ C
E = 5.0 X 10⁵ V/m
B = 0.80 T
ion's acceleration is zero
when acceleration is zero the magnitude of both the forces becomes equal.
q E = q V B
v =
v=
v = 6.25 × 10⁵ m/s ≈ 6.3 × 10⁵ m/s
hence, the correct answer is option C
Given,
Distance from the surface to the center of the earth, d=4000 miles
Distance from the center to you at a height of 8000 miles, a= 8000+4000=12000 miles
The gravitational force acting on a person at the surface is equal to his weight.
From Newton's Universal Law of Gravitation, the gravitational force is
Where G is the gravitational constant, M is the mass of the earth, m is the mass of the object/person, r is the distance between the center of the earth and the object/person
At the surface, this force is equal to the weight of the person, W=mg
i.e.
On substituting the of d,
At a height of 8000 miles from the surface, the gravitational force is equal to,
On dividing the above two equations,
Therefore,
Therefore at a height of 8000 miles above the surface of the earth, the force of gravity becomes 1/9 time your weight.