HELP!!!! SCIENCE!!!! I really need help!?

Question

#1) the gravitational force between two objects (mass1= 10 kg, mass2=6 kg) is measured when the objects are 10 centimeters apart. if the 10 kg is replaced with 20kg mass and the 6kg mass is replaced with 12kg mass, how does the new gravitational attraction compare to the first one measured?

#2)the gravitational force between two objects (mass1= 10 kg, mass2=6 kg) is measured when the objects are 10 centimeters apart. if the distance between then is increased to 40 centimeters, how does the new gravitational attraction compare to the first one measured?

#3) The gravitational force between two objects (mass1=1kg, mass2=2kg) is measured when the objects is reduced to 4 centimeters, how does the new gravitational attraction compare to the first one that was measured?

Please help me.... i really need to get these right! its very important and this is not my best subject..... And lots of other homework!!! please HELP!!

i messed up on writing #3

The gravitational force between two objects (mass1=1kg, mass2=2kg) is measured when the objects are 12 centimeters apart. if the 1kg mass is replaced with a 5kg mass, and the 2 kg mass is replaced with a 4 kg mass, and the distance between the objuects is reduced to 4 centimeters, how does the new gravitational attraction cmpare to the first one measured?

Answer 1

F = m_1*m_2*G/r² where m_1 and m_2 are the two masses, G is the gravitational constant, and r is the distance between their 'centers of mass'.

In 1, the product of the first masses is 10*6 = 60kg and the 2'nd case is 20*12 = 240kg so the force in the 2'nd case is 4 times that of the first case.

In 2, the distance between them is increased by a factor of 4 and 4² = 16 so the force will be 1/16 of what it was at 10 cm.

In 3. you haven't given any measurement value at any other distance so there's no way to answer it,


Doug

Answer 2

I assume you do not like math ...
I will not give you straight answers, instead i will give you a method on how to solve them. In my opinion it's better than just giving it out, this is simple stuff, what are you going to do when you are placed in front of a quiz?

First of all, your physics teacher gave out the formula for gravitation, use it.
F= Gm1m2/r^2

Note: (r^2 =r x r)
Note: We will use this ^ as the power sign

F = Magnitude of the Gravitational Force (N)
m1 = Mass of one body (kg)
m2 = Mass of a second body (kg)
G = 6.672x10-11 N.m2/kg2 (Universal Gravitational Constant)
r = Distance between the centers of mass of the two objects (m)

When solving such problems, always consider the units and convert to proper units. In your case here, you should look at the changing factor. In #1 the mass is changing, and it's already in KG so no need to worry. #2 The distance is changing and it's in cm, while the formula says it should be in m, so change to meters before doing anything...

How to solve these problems?
#1 You set m1=10, m2=6 and find F1. Where F1 is the force before the masses change.
Now consider F2,
F2 is the forcer after the masses change.
set m1=20 and m2=12, find F2.
When finding F1 and F2, keep all the constants in the formula as letters, no need to multiply them. Distance r did not change, keep it as r. G as G, don't go around multiplying big numbers, u'll waste your time. If r changes then change it (as in #2)
Now you will have F1 and F2, (forcer before and after)
Do F1/F2 and see what cancels out , you will come out with the final answer. r and G cancel, you will be left with a nice number. Basic math :)

Note: G/G=1 (use this when you do F1/F2)

I'll give you a hint on #2.
Since the distance changed, you will have to convert the distance into the right unit, especially when you got powers in your formula.

See r=10 cm=0.1m
Squaring r gives:
r^2=100cm^2=0.01m^2
see what happened

When r=40cm=0.4m
Squaring r gives:
r^2=1600cm^2=0.16m^2

The purpose of those problems is to let you know the effect of gravitation as different parameters change. If i were you i would spend some time on them, and if i can't on my own, i would seek out help, and not by posting the questions on a website. You (yes You) and in YOU need to know how to solve those questions so that you can solve bigger ones later on.

Good luck kid.

Answer 3

Well there are several ways you can answer this. One is by measuring the gravitational force by using the formula
GF = (G * m1 *m2)/ d^2
where GF = gravitational force m1&2 are your masses
D = distance between the two masses
G= 6.67 8 10^-8
Or you can just read the basics liste below..........
The gravitational force INCREASES as the objects mass becomes larger... Also the force INCREASES as the objects move closer together.
So for #1 : the attraction is stronger with larger masses

#2 The attraction is less because the objects are moved farther apart

#3 the attraction is stronger because the objects are moved closer together. Hope this helps

Answer 4

#1
F=(G*m1*m2)/d^2
You do not even need to know G to solve this. By doubling the mass of one you double the total force, by doubling the second mass you double the total force again.
First Force = 4.002x10^-9

The answer is the force is 4 times greater than the original force.

#2.
Same equation as above except now you have increased the distance, by dividing by a larger number the output is smaller than the original. The force will be 16 times weaker than the original (d^2 in the equation above is distance squared)

#3 F=(6.67x10^-11 * 1kg * 2kg)/4cm^2=8.3375x10^-10

the third is almost twice the force of the first.

Answer 5

F = G m1 x m2 / d^2 (Attractive force between mass m1 and mass m2, seperated by distance d. G = gravitation constant.) You need to understand this equation, as it is used for all 3 problems.

1) The equation shows the force is proportional to the product of the two masses. Since each mass doubles, the new force must be 4X the first one measured.

Mathmatically, ...

F1st = G m1 x m2 / d^2.
F2nd = G (2m1) x (2m2) / d^2 = 4G m1 x m2 / d^2 = 4 F1st.

2) Looking at the equation, the force is proportional to 1/d^2. Since d is increased by 4 times, the force is changed to 1/16th the first one measured.

Mathematically,....

F1st = K / (0.10)^2
F2nd = K /(0.40)^2 where K = G m1 x m2

F2nd/F1st = (0.1)^2/(0.4)^2 = 0.01/0.16 = 1/16.

3) This problem is similar to #2, but it looks like you are missing the original distance. "The distance was reduce from ?? to 4cm"