Will your weight be constant

Gravity is the force that pulls objects toward the centre of a planet or other celestial bodies. All the planets are kept in orbit around the sun by gravity. What else does gravity have to offer? Why do you land on the ground instead of drifting off into space when you jump up? When you throw or drop anything, why does it fall? Gravity is the answer: it’s an invisible force that attracts things to each other. The gravity of the Earth is what keeps you on the ground and helps you stand instead of float.

Gravity on Earth

Gravity is an essential part of our survival. We couldn’t survive on this planet without it. The sun’s gravity keeps Earth in orbit around it, allowing us to enjoy the sun’s light and warmth from a safe distance. It keeps our atmosphere and the air we need to breathe under control. Our planet is held together by gravity.

On the other hand, Gravity is not the same everywhere. Gravity is slightly stronger underneath where there is more mass than less mass. Likewise, it is different in poles and different towards the equator. 

Newton laws 

The gravitational pull can be explained using Newton’s Law of Universal Gravitation. The law stated that every heavy particle in the cosmos attracts every other massive particle with force directly proportional to their masses’ product. And it is also inversely proportional to the square of the distance between them.

We are surrounded by gravitational force. It helps us find how much we weigh and how far a ball travels before returning to the ground. The force exerted by the Earth on you is equal to the force exerted by you on the Earth. The gravitational force matches your weight when you’re at rest on or near the Earth’s surface.

Questions on the gravitational field are as follows: 

Question: If Dolly walks across the wire, strung horizontally across two 12m apart buildings. The dip(sag) in the rope is 8°. Her body mass is 75 kg. Determine the tension in the string? 

Solution: The first step is to know all the forces at work in this situation. The rope is being pulled down by the power of gravity (or her weight). This can be calculated using the formula: 

Fg = mg

Fg = (75 kg ) (- 9.8 m / s²)

Fg = – 735 N

The tension forces on each side of the wire as she stands in the midpoint combines other forces. Dolly is held up by these two tension forces, which will help her not to stumble. These two tension forces, on the other hand, these two tension forces are at an 8° angle to the horizontal side. It is necessary to examine the tension on the rope. As the rope is attached to both buildings, the X-components of each Tension force are equal in magnitude and opposite in direction. Each Tension force’s Y components are equal in magnitude and direction, keeping Dolly upright. As a result, the forces acting in the Y-direction can be summarised as follows:

Feet – Y = Fg + Ftension-y + Ftension-y 

You can simplify it, 

Feet – Y = Fg + 2Ftension -y 

Since the forces are balancing, the net force will be zero: 

0 = Fg + 2Ftension -y

The values we calculate above for the force of gravity can be used to find the tension in the y-direction. 

0 = -735N +2 Ftension– y 

735N = 2 Ftension– y

 Ftension– y = 367.5 N

In the Y direction, tension is created.  However, we need to find the overall tension of the wire. At this stage, you must apply trigonometric functions to calculate the wire’s hypotenuse (total tension).

You can use cosine to identify our hypotenuse as the Y-component of the Tension is on the other side of the triangle and forms an 8° angle.

Cos∅ = opp/ hypo

Cos(8) = 367.5 N/ hyp

Hyp x cos (8) = 367.5 N

Hyp = 367.5 N/ cos (8) 

Hyp = 371.1 N

Question: Will your weight remain constant when travelling to Greenland from brazil?

Answer: No, it will increase due to the acceleration. Also, gravity is more significant at poles and lesser at the equator. This is due to the oblate shape of the Earth; we often feel heavier when we travel to Greenland.  Your body will not show any changes, but the force of gravity and other forces combined will change when you reach the poles. 

Conclusion 

In the above article, we learnt the importance of Newton’s law. And why we weigh differently on poles and equators. As per the law, due to several forces acting altogether, our body doesn’t show changes, but the gravitational field is different around poles and the equator.