In classical mechanics, Newton's laws of motion are three laws that describe the relationship between the motion of an object and the forces acting on it. The first law states that an object either remains at rest or continues to move at a constant velocity, unless it is acted upon by an external force. The second law states that the rate of change of momentum of an object is directly proportional to the force applied, or, for an object with constant mass, that the net force on an object is equal to the mass of that object multiplied by the acceleration. The third law states that when one object exerts a force on a second object, that second object exerts a force that is equal in magnitude and opposite in direction on the first object.
The three laws of motion were first compiled by Isaac Newton in his Philosophiæ Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy), first published in 1687. Newton used them to explain and investigate the motion of many physical objects and systems, which laid the foundation for Newtonian mechanics.
Frictions are neglected in the system pictured. Here, a 1kg object released from above moves the car underneath. When this object falls off the car, what is its speed in m/s?
This question was asked from momentum conservation, but I didn't want to do it from there. Can you solve the question...
TL;DR Summary: Solutions to an exercise coming from the famous "Exercises for the Feynman lectures on physics".
I'm stuck on an exercise.
"A mass ##m## (kg) hangs on a cord suspended from an elevator which is descending with an acceleration of ##0.1g##. What is the tension T in the cord in...
to clarify , my purpose isn't to find a solution to my home work , I already did the home work and my thread is more a request of justification or at least a clarification of the forces at play. I need explanation on the general topic not the solution to my question, I am mentioning the question...
Hi,
I was thinking about a simple scenario in the framework of Newton (classic) mechanics.
Take a spring scale/balance fixed at one end (wall) with a body attached to the other end's hook. From an analysis point of view we can consider as "system" the spring scale + the wall + the body. Then...
The instantaneous velocity at time a is defined as derivative of motion function f(t). It is not similar to average velocity in an interval of time. From the Newton law. If an object is at rest, we must exert a force to make it move, assume that there is no friction. Depend on the weight of...
in the opposite problem that has three pulleys and two masses, the book is asking for :
1- the tension on the string.
2- the acceleration of pulley p1.
3- the acceleration of mass m2.
4- what should the mass "m" be such that m1 does not accelerate?
note : pulley p1 has mass m, in the diagram of...
Homework Statement
From reliable information, once Baron Münchhausen was stuck in a swamp, he pulled himself out of it by the hair. What laws of physics did the baron break? (Find the answer analytically)
Homework Equations
None.
The Attempt at a Solution
Well, I think that he breaks the...
Homework Statement
My question is not a homework problem. I am having difficulty in understanding the concept oof contact forces.
Homework Equations
What I don't understand is that when two bodies A and B are in contact and left on a frictionless surface, they apply normal reactions on each...
I know that n-body problem can be complicated, but that's for the dynamics. What about a static case:
e.g. if I have the distances of several bodies A, B and C etc. and their distance to a reference mass m, can I just use the vector addition of the Newton's gravitational force to add up all of...
1. A crate resting on a rough horizontal floor is to be moved horizontally. The coefficient of static friction is 0.40. To start the crate moving with the least possible applied force, in what direction should the force be applied?
a. Horizontal
b. 24 degrees below horizontal
c. 22 degrees...
Imagine a car that weights 1000Kg. Its engine pushes it forward with a force of 3kN. So the car is accelerating at 3m/s^2 (imagine there are no friction).
After 100 seconds (the speed of car at that moment is 300m/s, very realistic), the car hits a wagon that weighs 1000Kg, that is on rest. And...
Hi,
I teach a physics class to a group of homeschooled students. Many of them aren't yet at the level of algebra.
Last week we went over Newton's laws and did some experiments to show objects fall at the same rate regardless of mass. One student though, has asked me to explain why the mass...
These are conceptual questions, and i just want to really understand why the answer is the answer!
1. Homework Statement
1) A force acts to push two boxes, box 1 and box 2, across a floor (assume for this problem that friction is negligible). The two boxes are stacked such that the force...
So I understand the relationship between mass x acceleration=force but all that relationship tells me is "Whatever the force is to accelerate a given mass at a specific unit of acceleration = units of force, and we just accept whatever the unit of force is. example 1/ms² x 1 kg mass = 1 N...
Homework Statement
A uniform ring of mass m and radius r is projected horizontally with velocity v on a rough horizontal floor,so that it starts off with a pure sliding motion and it acquires a pure rolling motion after moving a distance d.If the coeffcient of friction between ground and ring...
Homework Statement
A 10 kg rubber box is resting on a concrete floor. A force of 200 N is then applied to this box in a horizontal direction. What is the magnitude of the friction force on the box?
Homework Equations
This is a question about applying Newton's laws so Fsmax = μs η and η = mg...
A cup of tea is removed from the fridge and left on a desk. The temperature of the room is constantly E and T(t) represents the temperature of the tea after t minutes.
dT/dt = K(E-T) Z(t) = E-T(t)
How do I find the general form of Z and T?
I have attached a picture so that it is easier to visualize this problem. The information is all in it. The number scribbles are just my attempts to solve it:
http://i65.tinypic.com/2qlbn9h.jpg
The current topic we are on in class is Newton's Laws and we have covered moments and equilibrium...
Homework Statement
Three identical charged balls of mass m and charge q bound in a triangle thread length l. One of the strands break. Calculate the acceleration of the middle ball at the initial moment.
2. Relevant equation
a. Newton's laws
##m\vec a_1 = \vec F_{12} +\vec F_{13} + \vec...
Hi Mentor
i am in little confusing about force, according Newton third law force on action and reaction is equal but according hydraulic system are not equal.
https://www.facebook.com/photo.php?fbid=1749685448591067&set=pb.100006488851023.-2207520000.1429362639.&type=3&theater
Thank you for...
If I jump, I accelerate away from Earth.
However, if I drop a human on the ground, he doesn't accelerate away from the Earth.
In both cases the force used on the Earth is about the same, but acceleration away from the Earth exists in one case and doesn't exist in another case. Why so?
(not a...
Homework Statement
Having problems on the method of calculating the acceleration due to gravity of the planet.
A certain planet has a diameter of 1715 km and a density of 5254 kg/m³. The planet has a moon that orbits every 4.46 earth-days.
What is the acceleration due to gravity...
Hello
I studied about the Newton law of Gravitation which states that in universe every matter attract each other with a force which is denoted by F= Gm1m2/r^2. But in my view it is only happen within the region of gravity of a matter. but not in the space.
please can anybody help me in...
Homework Statement
An object 50kg is hanged with a wire that wights 12,2kg
Homework Equations
what's the tension in the robe
The Attempt at a Solution
W - T = 0
(50+12,2)* 9,81 = 0
T = 610.182 N
Homework Statement
http://postimage.org/image/810vdcuvf/
Homework Equations
F=ma
The Attempt at a Solution
for part a) i put mdv/dt = -F(brake) - kv
but is lost for what to put in for part b), help?
Newton Law Gravitation - Multiple choice question??
Homework Statement
Newton’s law of gravitation can be applied to the Earth-Moon system. Which of the
following statements is not correct?
A The value of G at the surface of the Moon is the same as that at the surface
of the Earth...
A hot object cools down to a temperature of 10 degrees of Celsius during a period of 180 seconds. The room temperature is 10 degrees of Celsius. Assume the coefficient in the Newton's Law of cooling to be 0.01[1/sec]. Determine the original temperature of the substance
2. T(room) +...
Block A in the figure below has mass mA = 4.5 kg and is sliding down the ramp. Block B has mass mB = 2.2 kg. The coefficient of kinetic friction between block B and the horizontal plane is 0.50. The inclined plane is frictionless and at angle 30°.
part a is to find the tension
the equation...
A mass M at To =0 s has a speed of lVol in the positive X direction. The floor has a coefficient of static friction of Us and a coefficient of kinetic friction of Uk. How far will the mass M travel?
mass = M
@ To = 0s
speed = Vo
coefficient of static friction = Us
coefficient of Kinetic...
Consider the figure below where the coefficient of kinetic friction between the m1= 2.0-kg and
the m2 = 3.0-kg blocks is 0.30. The hanging mass is given to be m3 =10.0-kg and the horizontal
surface supporting the blocks along with the pulleys are...
I'm having some difficulty with some sample questions. I have the solution to the problems. but i don't know how to work through the problem to get to the solution.
1.what is the mass of the object?
details: Two strings are holding up an object. string 1 is 30 degree and 23N. string 2...
Homework Statement
pushing an armchair across a carpeted or at constant speed v you apply a force of 100N
if you push same chair at constant speed 2v(twice as fast) you mush push with a force?
a)100N
B)141N
The Attempt at a Solution
Newtons second law? if the net force acting on...
The paper is impressive. I'll get the link. Here
http://arxiv.org/abs/1003.1998
On our 2nd quarter 2010 MIP ("most important paper") poll, I noticed that Atyy picked both of the Randono papers. It made me think about this one, that came out in March---the first quarter of 2010, so not on the...
A 4kg block rests on a table. 5N is applied to it, pulling it the right, giving it an acceleration of 1ms^-2.
( a)If the applied force acts on the block for 5s, what will be the speed of the block at the end of this 5s be?
(b)After 5s, the applied force is removed. What will be the new...
Homework Statement
http://img69.imageshack.us/img69/2429/phyq1.jpg
Homework Equations
to find the acceleration of the 2 objects and the Tension Force.
The Attempt at a Solution
since only 1 pulley used, a=a1=a2, then
m1a=T (1)
m2a=-T+m2gsin45 (2)
i...
Homework Statement
An arrow, starting from rest, leaves the bow with a speed of 29.5 m/s. If the average force exerted on the arrow by the bow were doubled, all else remaining the same, with what speed would the arrow leave the bow?
Homework Equations
use a= v-vo/t and f=ma
The...
Homework Statement
Two boxes full of books are in contact with each other on a smooth table. Box H has twice the mass of Box G. If you push on box G with a horizontal force F, then box H will expereince a net force of?
Homework Equations
F =ma
The Attempt at a Solution
answer from...
Hello friends,
I have a problem in Bernoulli equation and Newton Law. I'm going to calculate how much power is needed to lift up an object with weight W.
I'm planning to put the object in a 10 inches diameter. How can I calculate the power needed by the motor to lift up the object? Does...
Homework Statement
I am trying to understand how these Newton's laws work, specifically with an object on an incline.
If a 5.00kg object is attached to a Newton spring scale on an incline (incline makes 30 degrees with the ground), what reading is the scale giving?
Homework Equations
Fx...
Homework Statement
If the maximum tension either rope can sustaine without breaking is 5000N determine the maximum value of the hanging weight that these ropes can safetly support.
the diagram shows two ropes connecting at a node which leads down to a weight,
the first rope on the left is...
[b]1. "two objects with masses 5kg and 2kg hang .6 m above the floor from the ends of a cord 6m long passing over a frictionless pulley. Both objects start from rest. Find the maximum height reached by the 2kg object.
Homework Equations
Newton's laws.
Kinematic equations.
The...
An applied force of 50 N is used to accelerate an object to the right across a frictional surface. The object encounters 10 N of friction. Use the diagram to determine the normal force, the net force, the mass, and the acceleration of the object. (Neglect air resistance.)
this is the image she...
hi there i have a question in which i can't get the answer i will show my work on what i did, if anybody can help , that would help a lot .
here is the question:
only two forces act on an object (mass= 3kg)
x=40N
a=60N is at 45 degrees above the horizon
y= ?
find...
I need some help on the two questions:
A 850 kg dragster, starting from rest, attains a speed of 24.6m/s in 0.49s.
1. What is the size of the average force on the dragster during this time interval?
Do I just use the equation F=ma to find this answer?...because I found the acceleration...
we all learn this law. It state that the force between two bodies of mass m_1 and m_2 is attractive in nature. The gravitational attraction F is directly proportional to the product of the masses of the two bodies and inversely proportional to the square of the distance between them.
From the...
It is almost time for the end of term exam and I am looking over my old exams and am confused by one problem. Masses m1,m2,m3,m4 are cnnected together(by a "string") on an incline theta = 22 degrees. m1 and tension = T1(connects m1 and m2) start nearest the bottem of the ramp, and a force F =...