Newton's laws Definition and 478 Threads

Duct Tape Challenge In this lab you and your group members will duct tape one of your members onto a wall using ONLY duct tape. The purpose of this lab is to understand forces and how they work. The rules for this challenge are below: • Each team consists of up to four team members • All...

Homework Statement A student tries to raise a chain consisting of three identical links. Each link has a mass of 380g. The three-piece chain is connected to a string and then suspended vertically, with the student holding the upper end of the string and pulling upward. Because of the student's...

Hey guys, I am new here and hope to be able to contribute with some of the discussions in Relativity. I will start my participation with a conceptual question that arised during my studies and has been boggling me since then. I have been studying Relativity using the book "A First Course in...

My question has to do with something Leonard Susskind, a professor of theoretical physics at Stanford University and director of the Stanford Institute for Theoretical Physics, said in one of his lectures. Basically that he didn't know why Newton wrote three laws of motion, when they could all...

"Newton's laws are the foundation stone of modern day mechanical engineering." Do you agree? Why?

Hey guys. I have long since realized that my interest and fascination for physics in general outweighs my mathematical skills by far. And since logic and common sense only gets you so far, I reach out to you with a sincere hope that you might help me see things more clearly. I'll start off...

Two toboggans are connected by a rope. The first toboggan has a mas of 60 kg and the second has a mass of 40 kg. The two toboggans are pulled by a rope connected to the first toboggan. If the force exerted on the rope is 250N [E], and friction between the toboggans and the ice and be ignored...

Homework Statement how do i solve it ? if someone can help I will appreciate it. Two masses m1 = m2 = 3 Kg and 5 Kg lie on two inclined planes with negligible friction connected via a cord that is inextensible and massless. The planes have angles of 30 degrees for m1 and 40 degrees for...

Homework Statement A 1.20 g spider hangs on its thread from the branch of a tree. A horizontal win blows the spider and the tread to an angle of 35 deg from the vertical. Find the force of win on the sider and the tension in the tread. Diagram...

I wanted to ask from my intuition of Newton's First law that body in motion remains in motion. Assume we kick a ball on earth, we does our force of kicking stops. I mean ultimately it comes to a stop due to resistance and gravity. Now, assume it is in space with no gravity or air. When we kick...

I'm trying to understand if a really heavy object on earth, say a mountain, would move if I push it with my bare hands. This sounds absurd but according to Newton's Laws, if I push against the mountain it will exert an equal and opposite force. I understand there are other forces like gravity...

Homework Statement A horizontal wire holds a solid uniform ball of mass m in place on a tilted ramp that rises 35.0° above the horizontal. The surface of this ramp is perfectly smooth, and the wire is directed away from the center of the ball.(a) How hard does the surface of the ramp push on...

I will try my best to explain this question: Block S (the sliding block) with mass M = 3.3 kg, is free to move along a horizontal friction-less surface and connected, by a cord that wraps over a friction-less pulley, to a second block H (the hanging block), with mass m = 2.1 kg. The cord and...

I was just thinking, are Newton's laws of motion most fundamental, or can they be reduced to something even simpler?

Homework Statement A meteor of mass .25 kg is falling vertically through Earth's atmosphere with an acceleration of 9.2 m/s. In addition to gravity, a vertical retarding force (due to the frictional drag of the atmosphere) acts on the meteor. What is the magnitude of this retarding force...

At the instant that one-fourth of block 1 remains on block 2, x2+l=x1+(l/16). For days trying to figure out how this equation derived from. Thank You. http://img15.imageshack.us/img15/3926/kotak.jpg

This conceptual question really got me thinking but I'm not sure how I would explain it: Your friend has been studying physics. She tells you that because of Newton's Third Law, she exerts a force on the Earth opposite to the force that it exerts on her. this worries her a lot because she...

Homework Statement Two Objects are hung from strings. The top object (m1) has a mass of 18 kg and the bottopm object (m2) has a mass of 12 kg. Looks like this...

Homework Statement A physics student playing with an air hockey table (a frictionless surface) finds that if she gives the puck a velocity of 3.44 m/s along the length (2.73 m) of the table at one end, by the time it has reached the other end the puck has drifted 2.08 cm to the right but...

1. Sean the skier is headed for a rough patch of snow with the coeffcient of friction 0.20. Find his acceleration if his mass is 50 kg. 2. F=ma, coeffcient of friction=Ff/Fn 3. Fgravity = 490.5 using the equation coeffcient of friction=Ff/Fn we get 0.20 = Ff/490.5 which equals Ff = 98.1 This is...

Newton's third law says that every force X exerts onto Y, Y exerts and equal and opposite force onto X. Ergo, if I'm standing on my linoleum floor, I'm exerting a force equal to my weight (mass x force of gravity) onto the floor and it's exerting an equal and opposite force on to me. However...

(1)A "swing" ride at a carnival consists of chairs that are swung in a circle by 10.0 m cables attached to a vertical rotating pole at an angle of 60 degrees with respect to the pole. Suppose the total mass of a chair and its occupant is 200 kg. (a) Determine the tension in the cable attached to...

A car which is originally at rest accelerates down a road with a net force of 32000 N acting on a 1980 kg car. At t = 12 seconds the driver slams on the brakes to avoid hitting a deer. Calculate the distance traveled by the car. Coefficient of kinetic friction for the rubber on pavement is...

Homework Statement A 89.6 kg man steps off a platform 4.52 m above the ground. He keeps his legs straight as he falls, but at the moment his feet touch the ground his knees begin to bend, and, treated as a particle, he moves an additional 0.88 m before coming to rest. Treating our rigid...

Homework Statement John (mass = 80 kg) rests on the top face of a light cube (mass = 0). A light rope passes horizontally from him over the front edge, and vertically down to Brian (mass = 60 kg) who hangs in contact with the front face as shown. The cube rests on a horizontal surface and...

Homework Statement Calculate the acceleration of a car given the fuzzy die hanging from a string attached to the roof of the car is deflected 15degrees to the vertical. The mass of the die is 250 g. Homework Equations F = ma Fg = mg and possibly many more! The Attempt at a Solution I don't...

Problem: "One 2.80kg paint bucket is hanging by a massless cord from another 2.80kg paint bucket, also hanging by a massless cord" a. Calculate the tension in the upper cord when the two buckets are pulled upward with an acceleration of 1.54m/s^2 by the upper cord. T1 = upper cord's tension...

We know that ##F=ma## or ##F=ma=m \frac{v}{t}##, so the acceleration is rate of slowing or speeding velocity, then does force changes the momentum ##p=mv## or ##p=Ft##. I'm waiting an answer, thanks!:)

Homework Statement For a birthday gift, you and some friends take a hot-air balloon ride. One friend is late, so the balloon floats a couple of feet off the ground as you wait. Before this person arrives, the combined weight of the basket and people is 1200kg , and the balloon is neutrally...

I've been lurking on PF for awhile now, but I reckon I'd benefit by actually trying to participate in the discussion and by asking my own questions once in awhile so, Hi all! In my second year I took a module on Classical Mechanics, and one of the things we covered was the Coriolis Theorem...

How would you show mathematically that Newton's laws, when taken as given, always yield a motion and that this motion is always unique (given initial positions/velocities) for arbitrary systems?

Homework Statement 1. For the system shown below use Newton’s Laws to clearly derive an expression for the acceleration of each mass and the tensions in the cord. The coefficient of friction between m1 and the incline is 0.100. The mass m1 is 3.00 kg, m2 = 8.00 kg, and θ = 35.0°. The...

Homework Statement A 880 N crate is being pulled across a level floor by a force F of 385 N at an angle of 27° above the horizontal. The coefficient of kinetic friction between the crate and the floor is 0.25. Find the magnitude of the acceleration of the crate. Homework Equations...

The first law of motion says that it takes force to accelerate something. The second law of motion says that F=ma. So now my teacher says that the first law is for inertial reference frames, while the second is for non-inertial reference frames. This really annoys me because I don't...

Homework Statement "A bicyclist can coast down a 5° hill at a constant 7.0 km/h. Assume the force of friction (air resistance) is proportional to the speed v so that Fair = cv." (a) Calculate the value of the constant c. (b) Calculate the average force that must be applied in order to...

Homework Statement A 54 kg woman is ice-skating toward the east on a frictionless frozen lake when she collides with a 79 kg man who is ice-skating toward the west. The maximum force exerted on the woman by the man during the collision is 160 N, west. Take east to be the positive direction of...

What is the magnitude of the force F (assumed horizontal) required to push the block up the plane at a constant speed? Take the coefficient of kinetic friction to be 0.25. Block is 75 lb I used Ff= mewN and found Wparallel Did Ʃ=ma Fapp-Ff-Wparallel= ma but i keep getting wrong answer

I think it's a pretty simple question. Let's say we're talking about a moving elevator in which a person stands on a digital balance. The textbook tells me to treat the downward direction as positive, so the value of acceleration is 9.8 m/s^2 instead of -9.8m/s^2 I'm asked to find out the...

Homework Statement If F = 8.0 N and M = 1.0 kg, what is the tension in the connecting string? The pulley and all surfaces are frictionless. Homework Equations F=ma The Attempt at a Solution 8-T=2a (2kg block) T - 1cos10? = 1a (for the 1kg block. I got stuck here, the angle threw...

A 1000kg boat is traveling at 90 km/h when its engine is shut off. The magnitude of the frictional force fk between boat and water is proportional to the speed V of the boat: fk = 70V where V is in meters per second and fk is in Newtons. Find the time required for the boat to slow to 45 km/h...

Homework Statement John (mass 80) rests on top of a light cube (mass = 0). A light rope passes horizontally from him over the front edge, and vertically down to Brian (mass 60kg) who hangs in contact with the front face as shown. The cube is on a horizontal surface and there is no friction...

1. Homework Statement If a 25kg mass has a constant velocity of 5m/s, when pushed horizontally by a 5 N force, what amount of resistance force is present? 2. Homework Equations F=ma 3. The Attempt at a Solution I'm pretty sure the velocity is irrelevant, ... I made a...

Homework Statement A student decides to move a box of books into her dormitory room by pulling on a rope attached to the box. She pulls with a force of 130.0 N at an angle of 15.0° above the horizontal. The box has a mass of 25.0 kg, and the coefficient of kinetic friction between box and...

two containers are connected by a cord (of negligible mass) passing over a frictionless pulley (also of negligible mass). At time t = 0, container 1 has mass 1.30 kg and container 2 has mass 2.8 kg, but container 1 is losing mass (through a leak) at the constant rate of 0.200 kg/s. a) At what...

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 roped of negligible mass. The girl exerts a horizontal 5.2N force on the rope. What are the acceleration magnitudes of (a) the sled (b) the girl (c) how far from the girl's initial...

How can you figure out the coefficient of static friction. I'm having a hard time understanding it.

An elevator cab and its load have a combined mass of 1600 kg. Find the tension in the supporting cable when the cab, originally moving downward at 12 m/s, is brought to rest with constant acceleration in a distance of 42m. Taking downwards as positive My solution: F net = mg - T = ma T =...

A 5.00-kg block is placed on top of a 12.0-kg block that rests on a frictionless table. The coefficient of static friction between the two blocks is 0.600. What is the maximum horizontal force that can be applied before the 5.00-kg block begins to slip relative to the 12.0-kg block, if the force...

Homework Statement Two weights are hanging by the following cables, A, B, C. 1. Find the tension in Cable A. 2. Find the tension in Cables B and C. -----ceiling---------- \ 60) (60 / \ / \ / B \ / C \ / \ / [_]...

Net force and Newton's laws of motion! Homework Statement A barge is hauled along a straight-line section of canal by two horses harnessed to tow ropes and walking along the tow paths on either side of the canal. Each horse pulls with a force of 490 N at an angle of 19° with the centerline...