How do you solve Newton's Law Problem with Answer

Hello welcome to Chafia pyhsic. In this post we will answer one of the big question in google about Newton's Law. The quaestion is How do you solve Newton's Law Problem?. Or how can we solve Newton problem.
The answer for this question is ... depend, the answer is depend on what situation or mechanism that you want to analyze with Newton's Law. But i will share with you the scheme or the flow that we can use to solve the problem.
First thing that you must to do to solve one problem is Draw all of posible vector and interaction on the object or problem you want to solve clearly. After that Interact all of the vector separetly on their own axes. Example: if you wanna analyze parabolic motion and you want to get the x and y equation of time, you must seperate the vector of velocity into x and y axes, and then interact all of vector appears in x and y direction. Finnaly subtitute all of constant that you know from the question to the equation that you get from interaction before.
Ok at least this three thing that i always be use to solve the problem.
Here i want to share with you some problem that i have been solved with Newton's Law in Halliday Book's. Hope it can help you.

A.Girl and Sled On Frozen Lake

A 40 kg girl and an 8.4 kg sled are on the frictionless ice of a frozen lake, 15 m apart but connected by a rope of negligible mass. The girl exerts a horizontal 5.2 N on the rope. What the acceleration of (a) the sled and (b) the girl?(c) How far from the girl's initial condition do they meet?
Answer:
To solve this problem first lets draw the scheme that girl and sled on ice.

In problem (a) and (b) we want to know the acceleration, so we write force applied in this two object seprately.

For the Sled:

For the girl's:

Now we have girl and sled acceleration, minus sign on sled acceleration show that sled is moving to the left. Now we want to solve the problem (c). If Girl and sled meet at point P we can daw the scheme before to be.

 If xoA is initial condition of girl and xpA is girl in P at t. we can write.

And for the Sled:

Since xpA and xps in same point at P, so xpA=xps.

Now we looking for t equation.

Subtitute t to xpA equation to get how far the girl from initial condition.

Oke now we kwon the girl move 2.6 m from the initial condition she exert the rope.

B.Accelerated Elevator

An elevator cab that weights 27,8 kN moves upward. What is the tension inthe cable if the cab's speed is. (a) increasing at a rate of 1.22 m/s^2 (b) decreasing at a rate of 1.22 m/s^2.
Answer:
For incresing speed:

We ger tension T = 31,26 kN
For decreasing speed:

We get tension T=24.3 kN

C.Human Cannonball atraction

The Zacchini family was renowed for their human cannonball act in which a family member wasshot from a cannon using either elastic bands or compressed air. In one version of the act, Emanuel Zacchini was shot over three Ferris wheels to land in a net at the same height as the opend end of cannon and at range of 69 m. He was proppeled inside the barrel for 5.2 m and launced at an 53 degree. If his mass was 85 kg and he underwent constant acceleration inside the barrel, what was the force proppeling him?
answer:

First let we know the velocity v in the open cannon with parabolic motion equation.

Now we seperate the velocity into x and y axes and then write the equation of motion in either axes.

For x axes:

For y axes:

Use a for y axes motion.

Now subtitute a to get ay.

Oke now we get ax and ay, next we subtitute this vector to Force equation.

The magnitude of F:

Allright i thinks thats all that i can share with you in this post. Hope it can help you. Thank you for read this post.

for Bahasa Indonesia version of this post visit Chafia Science : Soal Hukum Newton

Problem from : Halliday resnick. Fundamental of Physic 9th edition.