How Do You Solve Newton's Third Law Homework Problems?

AI Thread Summary
To solve Newton's Third Law homework problems, start by applying the second law's equation F=ma to determine acceleration and tension in the system. The total mass M is the sum of the three masses involved, while the tension T can be expressed as T1 + T2 + T3. For the first question, use the force of 100.0N to find the acceleration and individual tensions. For the second question, if T3 equals 15.0N, you can calculate the pulling force by considering the system's equilibrium. Understanding these relationships will clarify the problem-solving process.
forcefrom
Messages
11
Reaction score
0
Alright, so I have this sheet for homework and I'm not sure where to start.

Incase you are unable to see, the questions say:

a) What is the acceleration of the system and the tension in each rope if the girl lifts with a force of 100.0N?
b) What is the force that she pulls with if T3 (bottom bucket) = 15.0N?

http://imageshack.us/photo/my-images/696/photowda.jpg/

To begin, I know I need to utilize the second law's equation F=ma, but I do not know which masses I am supposed to use to find Fg = gm.

I need serious help, I am completely confused!
 
Physics news on Phys.org
To find the acceleration of the system, you can replace the entire system by an equivalent mass M and a tension T.

So M would be the sum of the 3 masses and T would T1+T2+T3 (they told you what 'T' was in the question.)

Just formulate the resultant force and you should get it now.
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

How do you identify the systems in which Newton's Third Law is obeyed?
Replies
6
Views
1K
Trivial question regarding Newton's Third Law and Elasticity
Replies
17
Views
2K
Newton's third law problem/kinematics (Airboat problem/no friction)
Replies
3
Views
4K
Understanding Newton's Third Law in Action: A Truck Pushing an SUV
Replies
4
Views
2K
Newton's Third Law Problem: Two masses, a rope and a pulley
Replies
21
Views
10K
Newton's Third Law: Explaining Why You Can't Lift Yourself
Replies
4
Views
2K
How Does Newton's Third Law Apply When a Bat Hits a Ball?
Replies
11
Views
3K
Newton's Third Law: Acceleration of box and worker
Replies
2
Views
5K
How Does Newton's Third Law Apply to Friction and Air Resistance?
Replies
18
Views
3K
Newton's third law force homework
Replies
19
Views
3K

Hot Threads

Recent Insights

Back
Top