physics help

[lord twiggy1]

holding it in you hand i think, it doesnt say

[misterman10]

holding it in you hand i think, it doesnt say

In that case, the only forces should be

1) The Normal Force
2) Weight (Mass x Gravity)

[OnlyAmbrose]

alright, another question. here goes: You hold an apple over your head. (A)Identify all the forces acting on the apple and their reaction forces. (B)When you drop the apple, identify all the forces acting on it as it falls and the corresponding reaction forces. Neglect air drag

A: Gravity. ALWAYS. Then there is the force your head is doing against the apple, to counter gravity.

I think that's it, it's not moving, so..

B: Gravity. I really feel this is imcomplete..

Someone else can answer better than me, I took physic quite a while ago...I don't know if I forgot something

This is it... there is no reactive force when you drop the apple, it's just gravity. Remember, the definition of "free fall" is that the ONLY force acting on an object is gravity.

[lord twiggy1]

i think its just gravity and your hand holding it. thats what i put before i asked the question at least. then for reaction to gravity i said: the gravity makes the apple want to go down. and for the force of your hand holding it up i said: the apple cant go down. is that right?

[misterman10]

i think its just gravity and your hand holding it. thats what i put before i asked the question at least. then for reaction to gravity i said: the gravity makes the apple want to go down. and for the force of your hand holding it up i said: the apple cant go down. is that right?

when your holding it, there is mass x gravity, and the normal force (force perpendicular to the surface)

when you drop it, its only gravity

[OnlyAmbrose]

i think its just gravity and your hand holding it. thats what i put before i asked the question at least. then for reaction to gravity i said: the gravity makes the apple want to go down. and for the force of your hand holding it up i said: the apple cant go down. is that right?

If an object is at rest, then the net force acting upon it must be zero.

So if you're holding an apple at rest, then the force of gravity is pointing downward, and you're exerting a "normal force" upward of equal magnitude as gravity.

[lord twiggy1]

alright, another question. here goes: You hold an apple over your head. (A)Identify all the forces acting on the apple and their reaction forces. (B)When you drop the apple, identify all the forces acting on it as it falls and the corresponding reaction forces. Neglect air drag

A: Gravity. ALWAYS. Then there is the force your head is doing against the apple, to counter gravity.

I think that's it, it's not moving, so..

B: Gravity. I really feel this is imcomplete..

Someone else can answer better than me, I took physic quite a while ago...I don't know if I forgot something

This is it... there is no reactive force when you drop the apple, it's just gravity. Remember, the definition of "free fall" is that the ONLY force acting on an object is gravity.

what about it hitting then bouncing/rolling of your head and falling to the floor?

[misterman10]

i think its just gravity and your hand holding it. thats what i put before i asked the question at least. then for reaction to gravity i said: the gravity makes the apple want to go down. and for the force of your hand holding it up i said: the apple cant go down. is that right?

If an object is at rest, then the net force acting upon it must be zero.

So if you're holding an apple at rest, then the force of gravity is pointing downward, and you're exerting a "normal force" upward of equal magnitude as gravity times mass.

fixed

[The Weird One]

this is what the homework help thread is for.

[OnlyAmbrose]

i think its just gravity and your hand holding it. thats what i put before i asked the question at least. then for reaction to gravity i said: the gravity makes the apple want to go down. and for the force of your hand holding it up i said: the apple cant go down. is that right?

If an object is at rest, then the net force acting upon it must be zero.

So if you're holding an apple at rest, then the force of gravity is pointing downward, and you're exerting a "normal force" upward of equal magnitude as gravity times mass.

fixed

Not fixed at all, actually. Gravity is a force.

I think what YOU mean is "acceleration due to gravity times mass". But an easier way to say that is just "gravity".

[lord twiggy1]

so what, maybe this isnt homework, maybe its me quizzing some physics geniouses compared to me

EDIT:pretend there is a quote of what TWO said above the text that starts with the word "so"

[misterman10]

i think its just gravity and your hand holding it. thats what i put before i asked the question at least. then for reaction to gravity i said: the gravity makes the apple want to go down. and for the force of your hand holding it up i said: the apple cant go down. is that right?

If an object is at rest, then the net force acting upon it must be zero.

So if you're holding an apple at rest, then the force of gravity is pointing downward, and you're exerting a "normal force" upward of equal magnitude as gravity times mass.

fixed

Not fixed at all, actually. Gravity is a force.

I think what YOU mean is "acceleration due to gravity times mass". But an easier way to say that is just "gravity".

but when you talk about normal forces, you cant say it is equal to gravity, because its not. The force exerted onto your hand is mass times gravity. Not gravity.

[OnlyAmbrose]

alright, another question. here goes: You hold an apple over your head. (A)Identify all the forces acting on the apple and their reaction forces. (B)When you drop the apple, identify all the forces acting on it as it falls and the corresponding reaction forces. Neglect air drag

A: Gravity. ALWAYS. Then there is the force your head is doing against the apple, to counter gravity.

I think that's it, it's not moving, so..

B: Gravity. I really feel this is imcomplete..

Someone else can answer better than me, I took physic quite a while ago...I don't know if I forgot something

This is it... there is no reactive force when you drop the apple, it's just gravity. Remember, the definition of "free fall" is that the ONLY force acting on an object is gravity.

what about it hitting then bouncing/rolling of your head and falling to the floor?

If the ball is bouncing or rolling, it is not in free fall, because it has the normal force of the floor acting upon it.

[lord twiggy1]

alright, another question. here goes: You hold an apple over your head. (A)Identify all the forces acting on the apple and their reaction forces. (B)When you drop the apple, identify all the forces acting on it as it falls and the corresponding reaction forces. Neglect air drag

A: Gravity. ALWAYS. Then there is the force your head is doing against the apple, to counter gravity.

I think that's it, it's not moving, so..

B: Gravity. I really feel this is imcomplete..

Someone else can answer better than me, I took physic quite a while ago...I don't know if I forgot something

This is it... there is no reactive force when you drop the apple, it's just gravity. Remember, the definition of "free fall" is that the ONLY force acting on an object is gravity.

what about it hitting then bouncing/rolling of your head and falling to the floor?

If the ball is bouncing or rolling, it is not in free fall, because it has the normal force of the floor acting upon it.

gotcha

[OnlyAmbrose]

i think its just gravity and your hand holding it. thats what i put before i asked the question at least. then for reaction to gravity i said: the gravity makes the apple want to go down. and for the force of your hand holding it up i said: the apple cant go down. is that right?

If an object is at rest, then the net force acting upon it must be zero.

So if you're holding an apple at rest, then the force of gravity is pointing downward, and you're exerting a "normal force" upward of equal magnitude as gravity times mass.

fixed

Not fixed at all, actually. Gravity is a force.

I think what YOU mean is "acceleration due to gravity times mass". But an easier way to say that is just "gravity".

but when you talk about normal forces, you cant say it is equal to gravity, because its not. The force exerted onto your hand is mass times gravity. Not gravity.

No, it's just gravity. Period. Gravity is a force.

Force = (mass)(acceleration)

I have no idea what mass times force equals, but it's not something necessary for IB physical science.

[misterman10]

No, it's just gravity. Period. Gravity is a force.

Force = (mass)(acceleration)

I have no idea what mass times force equals, but it's not something necessary for IB physical science.

Ambrose, you think you know these things but you don't. You just proved me right.

Force = mass x acceleration
Gravity is an acceleration of 9.8m/s^2
wheres the mass? Oh thats right, the mass of the apple

try again.

[OnlyAmbrose]

Let me put it this way: gravity does NOT equal 9.8 m*s^-2

ACCELERATION DUE TO GRAVITY (aka "g") equals 9.8 m*s^-2

Gravity (the force) = mg

[OnlyAmbrose]

Gravity is an acceleration of 9.8m/s^2

No, friend, gravity is a FORCE, which CAUSES an acceleration of 9.8 m*s^-2.

[lord twiggy1]

thanks guys i think ive figured this out. good night

[misterman10]

Let me put it this way: gravity does NOT equal 9.8 m*s^-2

ACCELERATION DUE TO GRAVITY (aka "g") equals 9.8 m*s^-2

Gravity (the force) = mg

And we are talking ABOUT FORCES
You cannot say that the normal force equals gravity, because thats what you said. The Normal Force = mg

Seriously, you don't know what your talking about right now. Although you may be correct, you stated that the Normal Force = gravity, and thats where you are wrong

[OnlyAmbrose]

Let me put it this way: gravity does NOT equal 9.8 m*s^-2

ACCELERATION DUE TO GRAVITY (aka "g") equals 9.8 m*s^-2

Gravity (the force) = mg

And we are talking ABOUT FORCES
You cannot say that the normal force equals gravity, because thats what you said. The Normal Force = mg

Seriously, you don't know what your talking about right now. Although you may be correct, you stated that the Normal Force = gravity, and thats where you are wrong

misterman, I'm in my second year of Physics. I know what I'm talking about.

I said that GRAVITY (the force) equals NORMAL FORCE.

This is absolutely 100% true. There is no need for correction.

Gravity times mass does NOT equal normal force.

However, normal force DOES equal mg, because mg equals GRAVITY.

But the expression "mg" is NOT "Mass times gravity"

"mg" is "Mass times ACCELERATION DUE TO GRAVITY".

"g" is not a force. it's an acceleration.

[misterman10]

Let me put it this way: gravity does NOT equal 9.8 m*s^-2

ACCELERATION DUE TO GRAVITY (aka "g") equals 9.8 m*s^-2

Gravity (the force) = mg

And we are talking ABOUT FORCES
You cannot say that the normal force equals gravity, because thats what you said. The Normal Force = mg

Seriously, you don't know what your talking about right now. Although you may be correct, you stated that the Normal Force = gravity, and thats where you are wrong

misterman, I'm in my second year of Physics. I know what I'm talking about.

I said that GRAVITY (the force) equals NORMAL FORCE.

This is absolutely 100% true. There is no need for correction.

Normal force DOES equal mg, because mg equals GRAVITY.

But the expression "mg" is NOT "Mass times gravity"

"mg" is "Mass times ACCELERATION DUE TO GRAVITY".

"g" is not a force. it's an acceleration.

wow, your second year
I'm taking a college level physics course right now.

MG does not equal gravity. How can a mass of say 12 times gravity = gravity? Oh wait, it cannot. You may know more about The Bible than me, but not physics.

[OnlyAmbrose]

Let me put it this way: gravity does NOT equal 9.8 m*s^-2

ACCELERATION DUE TO GRAVITY (aka "g") equals 9.8 m*s^-2

Gravity (the force) = mg

And we are talking ABOUT FORCES
You cannot say that the normal force equals gravity, because thats what you said. The Normal Force = mg

Seriously, you don't know what your talking about right now. Although you may be correct, you stated that the Normal Force = gravity, and thats where you are wrong

misterman, I'm in my second year of Physics. I know what I'm talking about.

I said that GRAVITY (the force) equals NORMAL FORCE.

This is absolutely 100% true. There is no need for correction.

Normal force DOES equal mg, because mg equals GRAVITY.

But the expression "mg" is NOT "Mass times gravity"

"mg" is "Mass times ACCELERATION DUE TO GRAVITY".

"g" is not a force. it's an acceleration.

wow, your second year
I'm taking a college level physics course right now.

MG does not equal gravity. How can a mass of say 12 times gravity = gravity? Oh wait, it cannot. You may know more about The Bible than me, but not physics.

I was in the class you were in last year, friend. I took AP last year and I'm in IB this year. Been there done that. Trust me, I've had this stuff till it came out of my ears.

Force of Gravity = mg.

ANY physics teacher will tell you that.

"g" does NOT EQUAL GRAVITY!!! How many times do you want me to tell you that? g = acceleration due to gravity!

F = ma. This is Newton's law.

If were talking about an object of mass 12 kg, then you use the equation to determine to FORCE of gravity upon it.

Force of gravity = (mass)(acceleration due to gravity)

F = mg

F = (12 kg)(9.8 m*s^-2)

F = 120 N (roughly)

Gravity is the F in this equation, NOT the "g".

[The Weird One]

*gets popcorn and sits down to watch the inevitable fight*

[misterman10]

Yes Ambrose, you just posted everything that I have been trying to tell you. You keep changing your story. The only thing so far I have disagreed with you is Normal Force = mg, when you said it did not.

Congrats on taking AP last year, as did I as a freshman