Physics question

[grave sentinel]

Why does Fg = mg?

F = ma is a completely seperate equation, and F is just = mg or ma but why would Fg = mg

[lilac salmon]

Fg means force of gravity or WEIGHT

Weight Is a force

Force is equal to ma

The acceleration in this case is gravity (9.81m/s^2 on earth)

[grave sentinel]

I mean

Since Force could equal mg or ma,

Wait no

[grave sentinel]

because W = mg itself

F = ma

[lilac salmon]

Yes

[grave sentinel]

I dont get it

[lilac salmon]

Wait what

[grave sentinel]

Yes though youre right, weight is a force

[lilac salmon]

Ok

[grave sentinel]

But how could Fg = mg

Because F = mg or ma

[lilac salmon]

It's just f = ma

Fg is force

F = mg is only true If f is weight

[grave sentinel]

I mean if youre talking about force due to gravity it would be F = mg

[lilac salmon]

Yes

[grave sentinel]

Ye

I still dont get it

[lilac salmon]

Wait is Fg confusing u

[grave sentinel]

ye that specific variable

Is it 2 variables

F(g) or Fg

[lilac salmon]

Oh I get it now

Hang on

[grave sentinel]

Alr

[lilac salmon]

Is the g in Fg subscript

[grave sentinel]

Subscript?

Wdym

[lilac salmon]

As In the g is small

Below F

[grave sentinel]

Uhhh

If I recall no

My physics teacher wrote it down during a practice problem

[lilac salmon]

Ok

It must be a function then

[grave sentinel]

A function?

[lilac salmon]

F(g)

The force is dependent on the gravity input I guess

[grave sentinel]

nah no way

Because

My teacher plugged in values into Fg = mg

I didnt get a chance to write it down but I can try to write it down if needed

[lilac salmon]

Can I see

[grave sentinel]

Yeah 1 sec

It was on a practice problem

Uh

A car weighing 14700 N is travelling at 30 m/s. The brakes are suddenly applied and the car skids to a stop. The frictional force between the tire and the road is 7100 N. How far will the car slide when the brakes are applied?

Ignore the 774kg I messed up but I can redo the question if needed

This is Work, Energy, and Power btw

[lilac salmon]

Oh ok

[grave sentinel]

But apparently

My teacher used Fg = mg to find the mass

I'm not sure how he did that

because he has g on both sides

[lilac salmon]

I'm pretty sure Fg meant to mean the force of gravity

[grave sentinel]

At first i thought i was gonna use f = ma to find mass

Wdym

[lilac salmon]

Wait nvm

[grave sentinel]

I am confused rn

[lilac salmon]

Same

But I think u use f = ma

[grave sentinel]

But why did he use Fg = mg i wanna know that

Is that a real eqt

[lilac salmon]

Don't think so

But yeah Fg probably stands for force of gravity

[grave sentinel]

Hm ok

Hey another question

So from the practice problem

[grave sentinel]

Do you use the W = 14700N to find the mass or the change in friction and force which is F = 7600?

[lilac salmon]

Use the weight

W = mg

Divide by g

I'd assume that this is no earth so the gravity is
9.81m/s^2

[lilac salmon]

That's how u do it

[grave sentinel]

Alr ty

.solved