What is Newtons laws: Definition and 121 Discussions
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.
Homework Statement
A ball of mass M is suspended by a thin string (of negligible mass) from the ceiling of an elevator. The vertical motion of the elevator as it travels up and down is described in the statements below. Indicate for each of the situations described the relation between value...
Homework Statement
1) A block is affected by three forces, and I have found the direction and magnitude of the resulting force, and thus the direction and magnitude of the acceleration. I know that the magnitude of the velocity vector for t = 5 is 4.7 m/s and that the distance traveled for t...
Why do we accept Newtons laws?
For every action, there is an equal and opposite reaction. why?
An object in motion tends to stay in motion. Why does it need a force to stop it?
Newtons laws...examples
I need to explain and illustrate examples of each of Newtons laws. They have to be different then all of the regular examples. ex. leaning against a wall. Any examples for me? And technical explination please
:confused: Homework Statement
A chair of mass 13.0 is sitting on the horizontal floor; the floor is not frictionless. You push on the chair with a force = 45.0 that is directed at an angle of 40.0 below the horizontal and the chair slides along the floor.
[b]2. Homework Equations...
I got this problem as part of a long homework packet, was able to figure out all the problems but the last 3, so here is one of them, but i don't have a book. I really have no idea on how to approach this problem, so i was hoping someone could lead me through it and help me figure it out...
I...
http://img.photobucket.com/albums/v638/ravenatic20/cablecars.jpg
Like my MS Paint skills? haha
The image shows a section of an alpine cable-car system. The maximum permissible mass of each car with occupants is 2800 kg. The cars, riding on a support cable, are pulled by a second cable...
Luggage is transported from one location to another in an airport by a conveyor belt. At a certain location, the belt moves down an incline that makes an angle of 2.5 degrees with the horizontal. Assume that with such a slight angle there is no slipping of the luggage. Determine the magnitude...
A 28.0 kg block is connected to an empty 1.00 kg bucket by a cord running over a frictionless pulley. The coefficient of static friction between the table and the block is 0.45 and the coefficient of kinetic friction between the table and the block is 0.320. Sand is gradually added to the bucket...
I have 2 questions that I am approaching, one seems very simple but I am still at a loss. The other I have attempted multiple times to no avail. Here they are:
1. An arrow, starting from rest, leaves the bow with a speed of 28.9 m/s. If the average force exerted on the arrow by the bow was...
At the local grocery store, you push a 15.2 kg shopping cart. You stop for a moment to add a bag of dog food to your cart. With a force of 12.0 N, you accelerate the cart from rest through a distance of 2.24 m in 3.00 s. What was the mass of the dog food?
F=ma m=f/a
I rearranged...
Ok the question is
Mass m1 is on an inclined surface at angle @ and is connected to a second hanging block with mass m2 by a cord passing over a small, frictionless pulley. the oeficient of static friction is u and the coefficient of kinetic friction is uk.
I first had to find m2 when m1 is...
You have just landed on Planet X. You take out a ball of mass , release it from rest from a height of and measure that it takes a time of to reach the ground. You can ignore any force on the ball from the atmosphere of the planet.
How much does the ball weigh on the surface of Planet X?
In the example i have A block (mass m1 = 22.1 kg) is on a surface inclined at = 33°. It is connected to a mass m2 = 11.2 kg by a massless cord passing over a pulley. The coefficients of friction are µk = 0.15 and µs = 0.25
It asks me for the magnitud of the friction.
After looking at this...
Can some one help explain?
A 20.0kg sled is being pulled across a horizontal surface at a CONSTANT VELOCITY. The pulling force has a magnitude of 80.0 Newtons(N) and is directed at an angle of 30 degreesabove the horizontal. What is the coefficient of kinetic friction?
Problem: Three forces in an xy plane act on 3.10 kg mass. 16.90 N directed at 46 deg, 7.20 N directed at 119 deg and 9.20 N directed at 218 deg . (all angles are measured from the positive x-axis, with positive angles in the counter-clockwise direction.) Calculate the magnitude of the...
iam really searching for the answer where does Newtons laws fail.i came to know that in some cases without the application of force there may be change in the momentum of the particle.how can this happen .can anyone quote the example.
what is a virtual work and how could it be possible...
I have this physics problem that has simply been driving me crazy...heres the problem:
Jenn coasts down the hill on a sled, reaching the bottom with a speed of 7.0m/s. The coefficient of kinetic friction between the sled's runners and the snow is .05, Jenn has a mass of 62 kg, and the sled has...
Having trouble with a homework problem on Newtons Laws, would appreciate any help:
An airplane flies in a loop (a circular path in a vertical plane) of radius 150m. The pilot's head always points toward the center of the loop. The speed of the airplane is not constant; the airplane goes...
Could anyone please help me with the following question? A rocket rises steadily upwards at a constant speed of 500 metres per second. Its initial mass is 5 x 10^4 kg; after 10 mins, this has decreased to 4.4 x 10^4 kg. Calculate the average force acting on the rocket during this time. This...