Newton's laws Definition and 478 Threads

Homework Statement A block of mass.5kg rests on the inclined surface of a wedge of mass 2kg. The wedge is acted on by a horizontal force F and slides on a frictionless surface. (a) If the coefficient of static friction between the wedge and the block is .8 and the angle of incline is 35...

Homework Statement A spacecraft is on a journey to the moon. At what point, as measured from the center of the earth, does the gravitational force exerted on the spacecraft by the Earth balance that exerted by the moon? This point lies on a line between the centers of the Earth and the...

1. An electron of mass 9.11 x 10^-31 kg has an initial speed of 4.00 x 10^5 m/s. It travels in a straight line, and its speed increases to 6.00 x 10^5 m/s in a distance of 3.00 cm. (a) Assuming its acceleration is constant, determine the force exerted on the electron. N (in the direction of...

A car that weighs 12000.0 N is initially moving at a speed of 30.0 km/hr when the brakes are applied and the car is brought to a stop in 4.1 s. Find the magnitude of the force that stops the car, assuming it is constant. Figured this one out, got: v0 = 8.33 m/s, a = -2.03 m/s^2, F = 2.49 X 10^3...

[SOLVED] Analytical Classical Dynamics: Newton's Laws Homework Statement Consider a system of N mutually interacting point objects. Let the ith object have mass mi and position vector ri. Suppose that the jth object exerts a central force fij on the ith. In addition, let the ith object be...

Newton's laws problems HELP! These are the problems that I either tried and thought I got the wrong answer :eek: or got half-way through and got completely stuck on. :bugeye: Any help would be greatly appreciated.:redface: Thanks! :wink: 1. A 43.8-kg sign is suspended by two ropes with...

[SOLVED] Newton's Laws of Motion PROBLEM! A gardener pushes down along the handle of a lawn mower of 20 kg mass with a force of 150 N. The handle makes an angle of 60 degrees with the ground. Calculate the horizontal acceleration of the mower if the coefficient of kinetic friction between its...

I have been absent for the past few days and he expects the class to these question but I was absent while he was teaching this so I have NO idea with to do here. 1st question: A 745 kg sled, initially at rest on a frictionless horizontal surface, is subjected to a force of 22500 N (E) for...

[SOLVED] Need help on a Newton's Laws problem :( Homework Statement A 56 kg ice skater holds up a large sheet of cardboard that can catch the wind and drive her (frictionlessly) across the ice. While she's moving at 0.5 m/s, a wind that is constant and horizontal for 5.0 s exerts a force on...

Homework Statement This is a question that's supposed to prove to us that you can use the work-kinetic energy theorem as a second theory of motion. Except I keep getting different answers when I work it out first w/ KET and second with Newton's Laws. So I'm definitely NOT fulfilling the...

A rocket-powered hockey puck has a thrust of 1.20 and a total mass of 1.50 . It is released from rest on a frictionless table, 3.20 from the edge of a 3.60 drop. The front of the rocket is pointed directly toward the edge. How far does the puck land from the base of the table? Okay...

Two blocks (5.0 kg and 6.0 kg) are connected through a frictionless system. Find the tension in the string and the acceleration of the system. The angle of the ramp is 45degrees. I have taken the direction of motion of each mass as the positive side. So this is what I did, For m=6kg...

1. What are the action/reaction forces when twirling a rubber stopper attached to a string? How does circular motion illustrate Newton's first law? 2. F=ma 3. I thought about centripetal and centrifugal, but my teacher said centrifugal force isn't a real force.

Here is the problem: A 12.5 Kg wooden crate with an initial velocity of 2.5m/s slides across a rough cement floor for 1.7 m before coming to rest. Find the coefficient of kinetic friction. (Use GUESS method.) The answer is 0.19. The equation you use is: coefficient = kinetic friction/normal...

Homework Statement A balloon with an attached basket and a total mass of 1200 kg is hovering at an altitude of 500m. A bag containing 100kg of sand is emptied over the side of the basket. Find the upward acceleration of the balloon after the sand has been poured out. Homework Equations...

Homework Statement A 1.0 kg mass (mA) and a 4.0 kg mass (mB) are attached to a lightweight cord that passes over a frictionless pulley. The hanging masses are free to move. Find the acceleration of the larger mass. Homework Equations Fnet = ma = FB-FA Fhanging object=m x acceleration...

Homework Statement Blocks X and Y of masses mx=5.12kg and my=3.22kg are connected by a fishing line passing over a frictionless pulley. Show that block X slides up the incline (35.7 degrees above the horizontal) with positive acceleration. Determine the magnitude of the acceleration...

Homework Statement According to legend, a horse learned Newton's laws. When the horse was told to pull a cart, it refused, saying that if it pulled the cart forward, according to Newton's third law there would be an equal force backwards. Thus, there would be balanced forces, and, according to...

This is mainly stumping me because of the absence of any force or mass. Homework Statement A crate is sliding down a ramp that is inclined at an angle of 33.6° above the horizontal. The coefficient of kinetic friction between the crate and the ramp surface is 0.485. Find the acceleration...

Homework Statement A block with a mass of 3.1kg is placed at rest on a surface inclined at an angle of 45 degrees above the horizontal. Th coefficient of static friction between the block and the surface is 0.50, and a force of magnitude F pushes upward on the block, parallel to the inclined...

A very small cube of mass m is places on the inside of a funnel rotating about a vertical axis at a constant rate of W revolutions per second. The wall of the funnel makes an angle A with the horizontal. The coefficient of static friction between the cube and funnel is us and the center of the...

Homework Statement A robot working in a nuclear power plant moves along a straight track. If it experiences a force F(t) = -Fi [ 1 + (4.0t - 2.0T)/T ] where T is a constant with the units of time, what is the instantaneous speed of the robot at the very end of the interval 0 \leq t \leq...

Two blocks, one M = 88kg, and a smaller one m = 16kg which is held to the bigger block by a coefficient of static friction between the two of us = 0.38, but the surface between M is frictionless. What is the minimum horizontal force required to hold m against M? the force of gravity acting...

Newton's Laws Problem--confused This has been frustrating me: Problem: The pulley in the figure is essentially weightless and frictionless. Suppose someone holds on to m=10.0 kg and accelerates it upward at 4.905 m/s/s. What will then be the tension in the rope given that M=10.0 kg...

My main question: Given an angle of incline, x, how can you find the coefficients of static and kinetic friction? Is it possible? My homework problem is: Someone wearing leather shoes is standing in the middle of a wooden plank. One end of the board is gradually raised until it makes an...

Because of the rotation of the Earth, a plumb bob may not hang exactly along the direction of the Earth's gravitational force on the plumb bob but may deviate slightly from that direction. a) Show that the deflection A in radians at a point at latitude L is given by A =...

A research balloon of total mass M is descending vertically with downward acceleration a. how much ballast must be thrown from the car to give the balloon an upward acceleration a, assuming that the upward life of the air balloon does not change. I figured that let Fu = upward lift force...

Homework Statement A 5.0-kg mass hangs at the end of a cord. Find the tensionin the cord if the acceleration of the mass is a)1.5 m/s squared up, b) 1.5 m/s squared down Answers: a) 57 N; b)42 N ____________________________________________________________________ A sample question in...

Homework Statement A rocket car is developed to break the land speed record along a salt flat in Utah. However, the safety of the driver must be considered, so the acceleration of the car must not exceed 5g (or five times the acceleration of gravity) during the test. Using the latest...

Homework Statement A 12000- kg helicopter is lifting a 4000- kg truck with an upward acceleration of 0.9 m/s2. Calculate the force the air exerts on the helicopter blades. Homework Equations F = ma The Attempt at a Solution I have no idea! Please help!

Homework Statement Two blocks m1 = 8.5 kg and m2 = 4.0 kg are connected by a homogeneous rope that has a mass of mr = 1.14 kg. A constant vertical force, F = 180.4 N, is applied to the upper block. What is the magnitude of the acceleration of the system? Homework Equations F=ma The...

Homework Statement A 12.0 kg monkey starts to climb a long rope to reach a banana located at a height of 7.00 m. The rope will snap if the tension exceeds 132 N. Calculate the least amount of time the monkey could take to reach the banana without breaking the rope. Homework Equations...

My question is which law of Newton is the most fundamental? I am talking of the laws of motion...

Homework Statement Peter and John are playing a game of tuf-of-war on a frictionless icy surface. Peter weighs 539N and John weighs 392N. DUring the course of the game, John accelerates toward Peter at a rate of 2.0m/s^2. a) What is the magnitude of the force that Peter exerts on John...

Homework Statement http://img201.imageshack.us/img201/6315/diagramyk1.gif -Assuming the system is frictionless, find m2 when it is accelerating down the ramp at 3.4 m/s2. Homework Equations -... F = ma? The Attempt at a Solution -In this problem, I tried tilting the axis so the...

Homework Statement A tether ball leans against the post to which it is attached. If the string to which the ball is attached is 1.80m long, the ball has a radius of .200m, and the ball has a mass of .500kg, what are the tension in the rope and the force the pole exerts on the ball? assume that...

Homework Statement HI, I am confused about how to approach this question. A 4.0 kg toboggan rests on a frictionless icy surface, and a 2.0 kg block rests on top of the toboggan. The coefficient of static friction m s between the block and the surface of the toboggan is 0.60, whereas the...

urgent-Newton's laws I need help with this question(halliday, resnick and walker, fifth edition, chapter 5 , question 14): PS: I can't draw the figure so I am explaining it as much as possible. 3 wooden blocks are pushed across a frictionless floor.The blocks have masses of 5kg, 2kg and...

Homework Statement A flywheel takes 5 seconds to rotate through 5 revolutions starting from rest. If it is accelerating at a constant rate during that time, what is the angular acceleration? Homework Equations ∅=ω t+at^2 The Attempt at a Solution having done my calculations i...

A tether ball leans against the post to which it is attached (Fig. 5-40). If the string to which the ball is attached is 2.00 m long, the ball has a radius of 0.300 m, and the ball has a mass of 0.400 kg, what are the tension in the rope and the force the pole exerts on the ball? Neglect any...

NEWTON'S LAWS: please help! :eek: so I am kinda stuck. problem: a 2.5kg basketball is dropped from the top of a building. its acceleration is found to be 9.4m/s2 as it drops to the ground. What is the force of air friction on the ball as it falls? so like... a=9.4 m-2.5kg...

Hi, This is more of a problem with concept rather than an actual mathematical problem, so forgive me if I don't use the template provided. I'm just having an issue with Newtons laws of motion. If I were to pull a box across a floor to the right with my hand, assuming that the mass of the box...

Homework Statement "while moving in a homeowner is pushing a box across the floor at a constant velocity. The coefficient of friction is .41. The pushing force is directed in a downward motion at and angle of theta below the horizontal. When theta's value is greater then a certain value...

a)In terms of theta,µk and w calculate F. b)for w=400 N and µk=.25, calculate F and theta ranging from 0 to 90 in increments of 10.Graph F versus theta. c)From the general expression in part (a) calculate the value of theta for which the value of F, required to maintain constatnt speed, is a...

I'd like guidelines on how to go about my assignment. I don't need the answers to the quetions, but rather an explanation on what should be in the answer. Below is the assignment, I need help with the bolded part of the quote and nothing else. Thanks alot! The ictalized parts are what I'm done with.

I performed a lab where I had to find the acceleration of two masses that were connected by a string and hanging on a pulley. The equation used was: http://home.earthlink.net/~copper017/Random/PhysicsLab/acceleration.jpg After performing the calculations I got the following data...

A block of mass 20kg is pushed against a vertical surface at an angle of 30 degrees as shown. The coefficient of friction between the surface and the block is 0.2. What is the minimum magitude of P to hold the block still? I got 271.5 when I tried but the answer is 202.2

How much of classical physics can be purely derived from Newton's 3 Laws of motion? Can Newton's laws derive conservation of momentum? Or any other conservation laws? Consider this example Let there be no external forces. When standing in a stationary bus and the bus accelerates forwards...

Is it possible to show directly from Newton's Laws that conservation of momentum and energy follow from principles of symmetry?

Homework Statement An athlete whose mass m is performing weight lifting excersies. Starting from rest positions, he lifts, with constant acceleration, a barbell that weighs w. He lifts the barbell a distance of x in time of t. Use Newton's laws to find the total force his feet exert on the...