Laws of motion Definition and 214 Threads

Homework Statement two particles of 2 kg and 3 kg are at rest . a 6 N force is exerted on the 3 kg particle at t=0. what is the speed of the center of mass at t=5s? Homework Equations F=ma v=u+atThe Attempt at a Solution first i applied f=ma to the 3 kg object and got 2 as the accn. And...

Homework Statement Block C is moving with a velocity v0 and block A and B are moving with velocities v1 and v2 with respect to block C. Find the relation between v0, v1 and v2 Homework Equations none The Attempt at a Solution Since the string is in-extensible, its velocity at both ends...

What is the best way to make a 9th grader understand the concept of force and laws of motion. Also please refer a book where he can get a good practice to solve force numericals. Please mention the ISBN code of the book also. Thanks a lot

hello I've just started learning physics my question is why do force increase while falling and stay constant while on the ground.i know force is increasing because in free fall things accelerate which according to Newton first law force must also go up. the force of gravity of Earth is 9.8N...

<<Mentor note: Edited for language>> 1. Homework Statement If I have a feather and a hammer and drop it at the same time from the same height (with out air resistance, so basically in a vacuum) Why would it land on the ground at the exact same time? Homework Equations F = ma The Attempt at...

I am a 10th grade student, and I tried for a few weeks now to find a proof to Kepler first and second laws. Is there a simple proof to Kepler' s laws?

I am trying to understand Bernoullis from Newton laws applied to molecular dynamics (as opposed to conservation laws) From the conservation laws I understand for a incompressible invicous (experiencing no friction effects ) Ideal fluid Mass is neither created nor destroyed Mass in = Mass...

Homework Statement A 225 kg crate rests on a surface that is inclined above the horizontal at an angle of 20o. A horizontal force (F = 535 N parallel to the ground, not the incline) is required to start the crate moving down the incline. What is the coefficient of friction between the crate and...

Homework Statement The drawing shows a large cube (mass = 25 kg) being accelerated across a horizontal frictionless surface by a horizontal force P. A small cube (msmall = 4 kg) is in contact with the front surface of the large cube and will slide downward unless P is sufficiently large. The...

Homework Statement A car with mass 2500 kilograms travels along a straight level road at 90 km/h. A headwind begins to blow with a force of 200 N causing the car to slow down. Calculate the car’s deceleration. Homework Equations The book uses the formula F =ma so 3. Book's solution = 0.08...

Homework Statement A truck (1200kg) is traveling south at 22m/s a) what is the net force required to bring the truck to a stop in 330m? b) what is the cause of this net force? (im assuming the answer is friction due to brakes) Mass= 1200kg (1.2*10^4) Velocity= 22m/s [south] What force is...

Homework Statement A cart of mass 1.5 kg is connected by a string over a pulley to a hanging mass of 300g. What would be the acceleration of the cart and mass if the force of gravity is approximately 1N for a 100g mass. Cart 1=1.5kg Cart 2=0.3 Kg Fg1=15N Fg2=3N Homework Equations F=ma The...

Homework Statement If two cars of equal mass are pushed apart by a spring mounted on cart #1 with a force of 14 N what will be the resulting acceleration of the carts. Mass of carts 1 and 2= 2.0Kg f=14N A? Homework Equations F=ma The Attempt at a Solution My theory is that the Newtons will...

Homework Statement A truck shown in the figure is driven with an acceleration a =3m/s2. Find the acceleration of the bodies A and B of masses 10 kg and 5 kg respectively, assuming pulleys are mass less and friction is absent everywhere. The Attempt at a Solution I have written three...

Homework Statement A body of mass 50 g is dropped from a height of 20 m. A boy on the ground hits the ball vertically upwards with a bat with an average force of 200 N, so that it attains a vertical height of 45 m. The time for which the ball remains in contact with the bat is (g = 10...

Definition/Summary Inertia is the phenomenon that a force is required to cause change of velocity. The amount of inertial mass of an object is measured by measuring how much force it takes to accelerate it. The symbol for inertial mass is m. Equations Extended explanation The...

Hey guys. So I have this question about this scenario.. If I have a glass of water on a table and I quickly pull the table cloth from under the glass, the glass stays put. I can't get my head around this. What causes this?

Homework Statement Mass of Block A = 1 kg Mass of Wedge B = 2 kg Inclination of Wedge is 37° and Cos 37° = 4/5 The wedge is given an acceleration of 5 ms-2 Find - 1. Acceleration of Block wrt Wedge 2. Normal Force Homework Equations Newton's Law for a System (hereby referred as...

Homework Statement A 2.0kg physics book is dropped from the roof of a skyscraper 240.1 m high. While the book is falling to the ground, a horizontal wind exerts a constant force of 11 N on it. Ignore air resistance. a. How far from the building is the book when it hits the ground? b. How...

I'm sorry I didn't use the outline provided automatically by the thread. My question does not focus on the maths; sorry if I chose the wrong section (I'm new here). Anyhow, what I'm asking is: Why does Newtonian Physics state that a moving object with uniform velocity (abiding by the...

When I had a school tour to A water park, there I observed that when a heavy boy used to slide down a water slide(and stop at β), he used to go further than where the ligher boy used to stop after sliding(α). But the friction will act more on Heavier then why is he going further?

Homework Statement In the arrangement shown, all surfaces are frictionless, mass of block M = 30 kg and m = 20 kg. If F = 180 N , Find accelerations of both the blocks 2. Doubt How much force will be applied on the larger block M by the pulley(coz of tension)? 1. T towards right 2. T towards...

Homework Statement Two blocks of mass m1 and m2 (m2 = 2 kg ; m1 = 3 kg)are connected with a spring moving on smooth plane. The acceleration of block of mass m2 is 2 ms-2, find acceleration of block with mass of 3kg. 2. The attempt at a solution Let external force of F be applied on Block...

Homework Statement In the arrangement shown, all surfaces are frictionless, mass of block M = 30 kg and m = 20 kg. If F = 180 N , Find accelerations of both the blocks 2. Doubt What amt of force will act on larger block M, just T(coz of horizontal string around the pulley) or...

The laws of motion -- rock sliding on a roof Homework Statement One side if the roof of a house slopes up at 37.0°.A roofer kicks a round,flat rock that has been thrown onto the roof by a neighborhood child.The rock slides straight up the incline with an initial speed of 15ms-1.The...

The photo shows below is my attempted solution. Is there any mistake so I cannot get the correct answer?

I attached an image of the problem I am currently working on. I am having a hard time understanding when to use cosine or sine when referring to the sum of the forces in the y direction or x direction. I have a general understanding as to where you initially place your coordinate system. If you...

simple i know but i have just hit a blank. a projectile of mass 250g traveling at 1200m/s impacts and sticks to a stationary 3500g object. What will be the resulting velocity of the two combined objects... Many thanks

Homework Statement A 0.075-kg arrow hits the target at 21 m/s and penetrates 3.8cm before stopping. (a) What average force did the target exert on the arrow? (b) What average force did the arrow exert on the target? (c) An identical arrow strikes the target at 42m/s. If the target exerts the...

Hi friends, The problem is from Newton's Laws. The problem is as follows: https://fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-ash4/1006364_1417581381802301_666606151_n.jpg IInd law states, Force, F = dP/dt => F = d(mv)/ dt Out come, If m is constant, v is variable, F =...

I'm new to this forum, so Hi! :) I have a test on Newton's Laws of Motion, the day after tomorrow and will appreciate any kind of help on these problems. Thank you very much, and nice to meet you all. :) -------- Q1. A particle of mass m moves with constant speed v on a circular path of...

A tangential force is appliied on pully hinged at its centre of gravity. will there be any reaction force at its center?? if yes then how much? will it be same as applies force? practically it seems there would be no force at its center?? and if force is applied from the both side say P1 and...

I've just started learning about torque, and understand that tau=Fd, but wondered how this relates to F=ma. For example if there is a rod with a pivot in the middle (say a nail), when one end is pushed down, why does the other end move up? Where is the force that causes the end to move up...

i) If a wall breaks when it gets hit by a cannonball, did the wall exert an equal and opposite force on the cannonball? ii) Would the force exerted by the cannonball on the wall only be the amount that was needed to break it? iii) Hypothetically, is it possible for the wall to break but...

Homework Statement A train moves off from a station and accelerates uniformly for 30.0 s over a distance of 225 m. It continues with the speed acquired for another 135 s, then the driver applies the brakes and the train comes to rest with uniform retardation at the next station in a further...

The three laws are already very simple and basic, is there any way to reduce them further?

Homework Statement find the radius R3=((T2GM/(4∏2))1/3 The Attempt at a Solution simple enough, my only question is when I plug in T (units: sec) G (units: m/s^2) and M (units: kg) there is nothing to cancel out the kg so my R is not in units of meters...the equation is correct because...

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...

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...

Homework Statement Fig. 4.3 A 5.0-kg block and a 4.0-kg block are connected by a 0.6-kg rod. The links between the blocks and the rod are denoted by A and B. A force F is applied to the upper block.In Fig. 4.3, the force in link B is 40 N. The acceleration of the blocks and rod assembly...

1. The distance between two telephone poles is 50.0 m. When a 1.00-kg bird lands on the telephone wire midway between the poles, the wire sags 0.200 m. (a) Draw a free-body diagram of the bird. (b) How much tension does the bird produce in the wire? Ignore the weight of the wire.2. this problem...

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

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

Homework Statement A rod AB is shown in figure. End A of the rod is fixed on the ground. Block is moving with velocity √3 m/s towards right. The velocity of end B when rod makes an angle of 60o with the ground. Homework Equations The Attempt at a Solution I assumed that at any...

Homework Statement Given in the pic .. . Homework Equations F=mg The Attempt at a Solution i think block 2 hitting wedge will take place 1st as the direction of displacement of B1 is perpendicular to 'g' .. . but i don't think that's a logical answer please answer and explain why

The first law seems obvious, plug in 0 for acceleration and you get 0 force. Therefore for something to accelerate there needs to be some net force. Also, wouldn't the third law have to be true if energy is conserved at all times? Sorry if this has been asked before.

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...

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...

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...

a) A shirt left on your bedroom floor is still there after 2 days. (Newton's 1 law) b) You run into your friend while ice-skating, & you both fall in opposite directions. (3rd law) c) The horse you're riding trips on a tree stump & stops quickly, & you fly forward. (1st law) d) A baseball...