# physics

posted by .

we can say that the force of gravity is equal to mass times acceleration were the acceleration is equal to gravity sense gravity is an acceleration because of newtons second law force = mass times acceleration

hence Fg = mass times acceleration
Fg = mass times gravity

Fg = mg

however newtons second law states that the net force acting on an object is equal to it's mass times it's acceleration so what allows us to say that

Fg = mg
because certainly not for every single situation the

net forc is going to equal to the force of gravity

• physics -

You are totally wrong in postulating the net force=force of gravity.

Nuts.

Force of gravity applies only to the gravitional field, and for a free falling object, Forcegravity=mass*a
But what about other forces? Any unblanced force = mass*acceleartion, whether or not gravity is involved.

Now what if an object is sitting on a shelf..it is not accelerating.
Fgravity=force upward by shelf. What about weight? The downward force is equal to its mass times the gravitional field strength. What is the gravitional field strength? It is commonly called g, and is equal to 9.8N/kg. That is the force per kilogram when under the influence of gravity. What if the object is dropped? what is its acceleration? It is g, or 9.8m/s^2. Hmmm. Note in units, N/kg=m/s^2

One nitpick of your writing, and is the reason I wrote this. Your statement "the acceleration is equal to gravity sense gravity is an acceleration because of newtons..." is inaccurate.

Gravity is not an acceleration, it is a force.

## Similar Questions

1. ### Physics

A 4.00kg crate is slowly lifted to a height of 1.50 m.(a)How much work is done by the lifting force?
2. ### physics

What does a 15 kg mass weigh on Earth? need assistance in setting up problem to get answer in Newtons and in pounds. thanks Weight in Newtons = M g =(Mass in kg) x (acceleration of gravity in m/s^2) The acceleration of gravity on Earth
3. ### Physics, 4 short questions

VERY IMPORTANT FOR AN ESSAY ASSIGNMENT. PLEASE HELP ASAP! THANK U VERYYYYY MUCH! 1. What force is needed to give a mass of 25 kg an acceleration of 20m/s squared?
4. ### motion and force

Consider a ball after it is thrown and going upward. The force on the ball is a). the force of gravity or b). some values between the force of gravity and the force of throw. What is the acceleration and what is the values of the acceleration. …
5. ### Physics

Could you please check my answers and help me out with the last two?
6. ### physics

Calculate the acceleration due to gravity on the moon. The moon\'s radius is about 1.74 E 6 m and its mass is 7.35 E 22 kg ok aparently there\'s an easier way to do this I applied Newtons second law in the radial direction net force …
7. ### AP Physics B

can you check my reasoning 1. The problem statement, all variables and given/known data ok well then... we did a lab were you have a hanging mass attached to a stirng that went through a straw and was attached to a rubber stopper. …
8. ### BOBPURSLEY or anyone

h t t p : / / w w w . j i s k h a .c o m / d i s p l a y . c g i ?
9. ### Physics

Ok work... work = net force parallel to displacement lets say something was pushed up a ramp at a constant velocity and you were asked how much work was done by pushing the block well the forces parellel to the displacement is the …
10. ### physics

an object has a weight of 5.10 Newtons at sea level, where the acceleration due to gravity is 9.81 m/s squared. What is the acceleration due to gravity on the object if it is placed in a spaceship 1,000 km above sea level which gravity …

More Similar Questions