i'm not sure witch statement is true
.The earth has a stronger gravitational pull than the Sun because it is smaller in mass.
.Planets would travel in a straight line if it weren't for the force of the Sun's gravity.
.The Sun's gravitational pull is weaker on planets that are closer to it.
.The elliptical path of planets is described by Newton's 1st law of motion.
To determine which statement is true, let's break down and analyze each one:
1. "The earth has a stronger gravitational pull than the Sun because it is smaller in mass."
To evaluate this statement, we need to recall Newton's law of universal gravitation. According to this law, the force of gravity between two objects depends on their masses and the distance between them. The equation for this force is F = (G * m1 * m2) / r^2, where F is the gravitational force, G is the gravitational constant, m1 and m2 are the masses of the objects, and r is the distance between them.
In this case, the mass of the Earth is indeed smaller than the mass of the Sun. However, the distance between the Earth and the Sun is much larger than any other factor involved. The large distance outweighs the difference in mass, contributing to the Sun having a much larger gravitational pull than the Earth. Therefore, this statement is false.
2. "Planets would travel in a straight line if it weren't for the force of the Sun's gravity."
Newton's first law of motion, known as the law of inertia, states that an object at rest or in motion will stay in that state unless acted upon by an external force. In the absence of any external forces, an object would indeed move in a straight line at a constant speed.
However, the gravitational force of the Sun acts as an external force on planets, causing them to deviate from straight-line motion. Therefore, this statement is true, as it acknowledges the influence of the Sun's gravity on the curving paths of planets.
3. "The Sun's gravitational pull is weaker on planets that are closer to it."
This statement is false. According to Newton's law of universal gravitation, the strength of the gravitational force between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. Hence, the closer an object is to another object, the stronger the gravitational force acting upon it.
Therefore, the Sun's gravitational pull is stronger on planets that are closer to it, not weaker. This statement is incorrect.
4. "The elliptical path of the planets is described by Newton's 1st law of motion."
Newton's first law of motion, also known as the law of inertia, cannot wholly explain the elliptical paths of the planets. The elliptical orbits of the planets are accurately described by Kepler's laws of planetary motion, not Newton's first law.
Kepler's laws state that planets move in elliptical orbits with the Sun at one of the focal points. This specific behavior of planetary motion is not addressed by Newton's first law alone. Therefore, this statement is false.
In summary, out of the given statements, the only true statement is: "Planets would travel in a straight line if it weren't for the force of the Sun's gravity."