does newton's first law mean that we don't need gravity to be attracted

no, it just means that a brick isn't gonna move unless something makes it move. if in the air, moves down because of gravity. if on floor, doesn't move unless something has it move, like a hand pushing the brick. first law is that an object will stay at rest or motion unless another force acts upon

Grant

yeah but once gravity has already been exerted .. i am saying that it need not be constantly exerted now according to newtons first law

Dharmee

gravity is constantly being exerted. gravity is the force of attractiveness between two objects. you and another person exert a force on each other but the reason you two don't come together is because earth's effect on both of you is much greater

Grant

maybe the reason we dont come together is our inertia only and not gravity

Dharmee

this is the definition of inertia: a property of matter by which it continues in its existing state of rest or uniform motion in a straight line, unless that state is changed by an external force.

Grant

the earth has a much higher affect on us force wise that me and you together on each other, that's why we don't attract, relatively speaking of course

Grant

quite clear explanation but i just want my mind to be open to any theory at all .. its possible that maybe gravity does not exist at all or even the opposite can be true .. i dont want a fixed state of mind thats all

Dharmee

why wouldn't gravity exist? gravity is just the attractive force between two objects, at least to my understanding.

Grant

earth moves in a circular motion so yes it does need a constant force for a circular motion but incase of objects on earth i feel maybe there is no force of attraction towards the centre and its our inertia forcing us to stay at a point as once gravity had acted on the object

Dharmee

why should it exist .. i mean its all an assumption and the evidences are empirical

Dharmee

We have equations to prove it and lies of evidence to support. we orbit because we have a velocity and the sun is pulling us. Gravity is a law, we know it exists.

Grant

yeah sure there are equations but they are based on observations and assumptions

Dharmee

g is obtained by a simple pendulum experiment ...

Dharmee

gravity is tested by dropping a rock...

Grant

and also there were so many newtonian laws proved wrong by einstein . jus saying that its a law doesnt mean it cant be wrong

Dharmee

pendulum is good for showing energy transfer, here is an article on the detection of gravitational waves: ***ligo.org/detections.php

Grant

yeah but g is calculated by pendulum oscillations ..

Dharmee

thats what .. einstein s fabric model explains that force of attraction by sun on earth but i am talking about force of attraction by earth on objects on earth

Dharmee

no... this is how gravity is calculated:F = G*((m sub 1*m sub 2)/r^2)

Grant

gravitational constant is obtained EXPERIMENTALLY

Dharmee

Calculate the time of one oscillation or the period (T) by dividing the total time by the number of oscillations you counted. Use your calculated (T) along with the exact length of the pendulum (L) in the above formula to find "g." This is your measured value for "g."

Dharmee

G is the universal gravitational constant. F is the gravity

Grant

search up the gravity equation

Grant

yeahh G is obtained experimentally

Dharmee

thats what .. after all its EXPERIMENTALLY calculated so its empirical

Dharmee

yes... so where do we disagree?

Grant

its empirical whixh means it can be proved wrong

Dharmee

so cant just say why wouldnt gravity exists

Dharmee

the constant, sure but extremely unlikely it is wrong. gravity however exists, there are equations and loads of support surrounding the concept. unfortunately I don't have a high enough background in physics but have this discussion with a physicist

Grant

can u suggest a platform where i can?

Dharmee

stack exchange, physics section***

Grant

there is! it is also a website as well

Grant

nice talking to you

Dharmee

***physics.stackexchange.com/

Grant

A spring with 50g mass suspended from it,has its length extended by 7.8cm
1.1 determine the spring constant?
1.2 it is observed that the length of the spring decreases by 4.7cm,from its original length, when a toy is place on top of it. what is the mass of the toy?

solution
mass = 50g= 0.05kg
force= 50 x 10= 500N
extension= 7.8cm = 0.078m
using the formula
Force= Ke
K = force/extension
500/.078
= 6410.25N/m

Sampson

1.2
Decrease in length= -4.7cm =-0.047m
mass=?
acceleration due to gravity= 10
force = K x e
force= mass x acceleration
m x a = K x e
mass = K x e/acceleration
= 6410.25 x 0.047/10
= 30.13kg

Sampson

you should explain how yoy got the answer Anita

Grant

with the fomular F=mg I got the value for force because now the force acting on the spring is the weight of the object and also you have to convert from grams to kilograms and cm to meter

Anita

so the spring constant K=F/e
where
F is force and e is extension

Anita