Answer:
According to the gravitational law of Isaac Newton, "the gravitational force between any two objects is proportional to the product of the objects’ masses and inversely proportional to the square of the separation between their centers".
Therefore gravitational constant is the proportionality constant used in Newton’s Law of Universal Gravitation, and is commonly denoted by G. It is expressed as:
F= Gm1m2/r2
Another scientist Cavendish was able to measure the gravitational force and the value of the proportionality constant. It is expressed as G = 6.673×10-11 N m2 kg-2.
Answer:
635 years old
Explanation:
The light reaching the earth from the sun will travel at a speed called the speed of light, and this has a universal value of 3 × 10⁸ m/s. Bearing this in mind, let us calculate the age of the light reaching the Earth from the sun:
Distance of star from Earth = 6.1 × 10⁸m
Speed of light = 3 × 10⁸ m/s
We have distance and speed, let us calculate the time of travel of the light from the star to the earth.
Distance = speed × time
6.1 × 10⁸ = 3 × 10⁸ × time

In order to do the division above, we will divide the whole numbers normally, then we will apply the law of indices to the power that says:
Xᵃ ÷ Xᵇ = X⁽ᵃ⁻ᵇ⁾

Next, we are told that there are 3.2 × 10⁷ seconds in a year.
∴ The number of years travelled by the light from the star:

please note that:
2.03 × 10¹⁰ = 20300000000
3.2 × 10⁷ = 32000000

The closest answer in the option is 635 years, and we are short of this by some points due probably to approximations in the calculation.
Answer:
Five Characteristics of a Mineral
Minerals Are Natural. You must find minerals in nature; substances concocted in laboratories don't qualify. ...
Minerals Are Inorganic. ...
Minerals Are Solids. ...
Definite Chemical Composition. ...
Crystalline Structure.
These are just some examples.
Explanation:
Which body is in equilibrium?
(1) a satellite orbiting Earth in a circular orbit
. No. The forces on it are unbalanced. There's only one force acting on it ... the force of gravity, pulling it toward the center of the Earth. That's a centripetal force, and the satellite is experiencing centripetal acceleration.
(2) a ball falling freely toward the surface of Earth. No. The forces on it are unbalanced. There's only one force acting on it ... the force of gravity, pulling it toward the center of the Earth. The ball is accelerating toward the ground.
<em>
(3) a car moving with a constant speed along a straight, level road. YES.</em> We don't even need to analyze the forces, just look at the car. It's moving in a straight line, and its speed is not changing. The car's acceleration is zero ! That right there tells us that the NET force ... the sum of all forces acting on the car ... is zero. THAT's called 'equilibrium'.
(4) a projectile at the highest point in its trajectory. No. The forces on it are unbalanced. There's only one force acting on it ... the force of gravity, pulling it toward the center of the Earth. The projectile is accelerating toward the ground.