**Answer:**

The weight of the person would **increase**

**Explanation:**

The Universal Law of Gravitation gives the magnitude of the force between the masses of two objects (m1 and m2) separated a given distance "d" as:

where G is the universal gravitational constant.

Our weight on Earth is this force between the Earth (of mass M) and ourselves (our mass m) at a distance that is the Earth's radius R:

Now, if we keep all the values equal (mass of the Earth M and our mass m) except for the distance between the center of the Earth and our center of gravity (the radius of the Earth), we are going to have now a smaller radius (r) in the formula above:

and dividing by a smaller number (r is **smaller** than R), will render a **larger** quotient. This means that the actual force (weight) will become **larger**, so the weight would clearly **increase**.

**Answer:Friction force**

**Explanation:**

The frictional force is responsible for stopping the moving object.

The friction force is provided by nature in the form of air resistance, fluid resistance, Surface resistance.

For surface resistance, the friction force is of two types namely kinetic friction force and static friction force.

Static friction acts when the object is stationary and a force is applied to cause the motion while kinetic friction acts when the body starts moving.

kinetic friction is lesser is in magnitude as compared to static friction.

**Answer:**

the required charged is **7.06 × 10⁻¹³ C**

**Explanation:**

Given that;

Radius = 30 microns = 30 × 10⁻⁶

Speed v = 20 m/s

length x = 1.6 cm = 0.016 m

spacing d = 1.0 mm = 0.001 m

Voltage V = 1500 V

from the question, the electric field between the plates is uniform and equal to Voltage divided by the distance between the plates.

Electric field E = V/d

E = 1500 V / 0.001 m

E = 1.5 × 10⁶ V/m

Mass of ink drop m = **p**v

m = 10³ kg/m³ × πr³

m = 1000 kg/m³ × π × (30 × 10⁻⁶)³

m = 1.131 × 10⁻¹⁰ Kg

Time taken to travel t = x / sped

t = 0.016 m / 20 m/s

t = 0.0008 s

From the kinematic equation

to form the top of a letter 3 mm ( 0.003 m )high

y = at²

2y = at²

a = 2y/t²

we substitute

a = (2 × 0.003 m) / (0.0008 s)²

a = 9375 m/s²

Now Force F = Eq = ma

so

q = ma / E

we substitute

q = ( 1.131 × 10⁻¹⁰ Kg × 9375 m/s² ) / ( 1.5 × 10⁶ V/m )

q = **7.06 × 10⁻¹³ C**

Therefore, the required charged is **7.06 × 10⁻¹³ C**

The problem of the "sound barrier" has to do with moving through

air, and the things the air does when you try to push it out of the

way faster than the speed of sound. Moving through air faster

than sound was an engineering and technological problem, not

a scientific one.

Concerning light, that's about **874 thousand times** faster.

See the problem ?