Net force Definition and 496 Threads

Homework Statement A 3.00 Kg object is moving in a plane, with its x and y coordinates given by x=5t^2-1 and y=3t^3+2, where x and y in meters and t in seconds. Find the magnitude of the net force acting on this object at t=2.00 secs. Homework Equations The Attempt at a Solution...

Homework Statement In a cathode ray tube, electrons are accelerated from rest by a constant electric force of magnitude 6.4E-17 N during the first 2.0cm of the tubes length; then they move at essentially constant velocity another 45cm before hitting the screen. A) Find the speed of the...

[SOLVED] Two point charges, Zero Net Force Homework Statement Two point charges of charge 7.40 μC and -1.80 μC are placed along the x-axis at x = 0.000 m and x = 0.300 m respectively. Where must a third charge, q, be placed along the x-axis so that it does not experience any net force because...

Homework Statement The speed of a particle doubles and then doubles again because a net external force acts on it. Does the net force do more work during the first or the second doubling? Justify your answer. Homework Equations I'm not sure, but i think E = 1/2 mv(squared) The...

I have a problem in trying to express a net force equation for a falling elastic object when collision ensues. For instance, you drop a spring with a spring coefficient k. the spring compresses a distance x after a time t for a maximum time of tf and distance xf. the spring has a weight W...

Homework Statement The Bruce Nuclear Development is a CANDU style reactor. This means that it has a "vaccum building" to "suck" (the contents of a malfunction reactor to a safer place. Refer to the engineering "specs" for the needed information to calculate the net force of the atmposhere...

[SOLVED] Net Force of object changing velocity Hi, I'm studying for a test, so there might be a few of these in the next hour or so. Homework Statement A supertanker of mass 1.0 X 10^{8} kg travels 3.5km, reaching a speed of 4.1km/h from rest. What was the magnitude of the unbalanced force...

[SOLVED] I really need help I understand the very simple questions and all, but when the book throws all these extra things at me, I get so lost. You might've remembered my earlier post (my first one), so I'm back with a bit more. If it takes a human cannonball 1.5s to exit a 1.6m long...

Homework Statement will a body necessarily remain at rest if the net force acting on it is zero?give a reason for ur answer...and I've just passed my ninth grade so if u cud please it to me explain at that level...:smile: Homework Equations The Attempt at a Solution

Forces/Friction I'm new, so I'd like to say thanks in advance for helping me. The site wants all answers to the 4th decimal place. Idk how stuff normally works around here, but a small explanation with the answer would help me understand this stuff better. 1. Three forces act on a particle...

Homework Statement g=10m/s^2 A fully loaded Saturn rocket has a mass of 2.92x10^6kg. Its engines have a thrust of 3.34x10^7N. a) How much does the rocket weigh. answer 2.92x10^7 N b) What is the net force on the rocket when it blasts off? answer 4.2x10^6N c) What is the...

1. A man is lazily floating on an air mattress in a swimming pool. If the weight of the man and air mattress together is 740 N, what is the upward force of the water acting on the system of man and mattress? 2. A truck driving on a level highway is acted upon by the following forces: a...

Homework Statement I really can't see where I am going wrong here. I would latex out my work, but it would take way too long, so I have scanned it in. It should be easy enough to read though. Its NUMBER 7, fig 21-22 Also the blurr says '100 nC' The Attempt at a Solution

Homework Statement Particles 2 and 4, of charge -e, are fixed in place on the y-axis at y2=-10.00 cm and y4=5.00cm. Particles 1 and 3, of charge -e, can be moved along the x axis. Particle 5 of charge +e is fixed at the origin. Initially particle 1 is at x1= -10.0cm and particle 3 is at x3=...

Homework Statement A 65 kilogram tightrope walker falls vertically downward with a velocity of 9.9m/s. She falls into a net which stretches 1.5m vertically as it breaks her fall. What is the average net force on the walker as her fall is being broken, and what is the G force that she...

[SOLVED] Net Force Question with no velocity or time given. Homework Statement A ball of mass 0.6 kg flies through the air at low speed, so that air resistance is negligible. What is the net force acting on the ball while it is in motion? Homework Equations Fnet = m(change in...

Homework Statement An airplane is flying at an elevation of 12500 m. The window on an airplane is a square of length 0.115 m on each side. What is the net force on the window? Homework Equations P = Po + pgh p = 1.26 kg/m^3 Pair = 101.3 kPa The Attempt at a Solution I thought...

Hi, I would like to first open this post by saying that I am not a slacker, and I try my hardest to figure things out to the best of my abilities. I am in Physics 1 right now. We are studying what our book calls Forces in One Dimension. I have a problem, the problem being I have a...

help, please :) Homework Statement Two masses are suspended by a string placed over a pulley supported by the ceiling (m1 = 2.20 kg and m2 = 7.70 kg) Consider up to be positive. What is the acceleration on the 6.20 kg mass? The net force? What is the acceleration on the 7.70 kg...

Help Me Please! You don't have to actually do this, but does anyone know how to so I can solve it myself? :confused::rolleyes: 1) A 50 Newton horizontal force is needed to keep an object weighing 500 Newtons moving at a constant velocity of 2.0 m/s across a horizontal surface. What is the...

Homework Statement A box of mass, m, is on a plane inclined at an angle, q, relative to the horizontal. The coefficient of kinetic friction between the box and the incline is uk, and the body is accelerating down the incline. What is the net force on the body? The Attempt at a Solution...

We're learning about a systems center of mass and have: F_{net} = Ma_{com} But I having a problem understanding why the net force is only from external forces? Is it because internal forces follow Newtons third law so the net force from internal forces is 0? If that's the case then take...

Consider 3 force vectors F1, F2, and F3. The vector F1 has magnitude F1 = 55N and direction θ = 41°; the vector F2 has magnitude F2 = 20N and direction θ = - 140°; and the vector F3 has magnitude F3 = 17N and direction θ = 140°. All the direction angles θ are measured from the positive x axis...

A 1kg ball rolls along a circular track that is banked at 20 degrees. The normal force on the ball is 10.43N, tilted inward. The radius of the track is 10m. a. What is the net force on the ball (include direction)? b. How fast is the ball going for it to complete the turn? possible...

Homework Statement A skier goes down a slope with an angle of 35 degrees relative to the horizontal. Her mass, including all equipment, is 70 kg. The coefficient of kinetic friction between her skies and the snow is 0.15. A. Please draw a free-body diagram of the skier. B. Calculate the net...

[SOLVED] The NET FORCE and a lawnmower Homework Statement Well I am working on a question here and am finding trouble with one part. The answers are in brackets. The trouble I am having is with part c, where i believe you have to find the accleration then the time to work out power which is...

Can someone explain to me why putting different weights in certain angles can alter the force. I was just doing a lab in class using a force table, where the weights dangled and you have to prevent the ring from touching the pole in the center. If the mass of the object doesn't change and ( I'm...

My physics teacher told my class that in order for there to movement, there must be a net force on an object. He also said that when an object reaches terminal velocity the Fnet is zero because air resistance equals that of the object's weight. Then, he said that the object continues to fall...

Homework Statement An 8.0Kg rocket is fired and encounters a force of air resistance of 4.9N. If the rocket's engines applied 100N of thrust: A. What is the Net Force on the rocket? B. What is the Rocket's Acceleration? Homework Equations (A) F=MA (B) Is it (Vfinal - Vinitial)/T? The...

Homework Statement A crate is pulled to the right (positive x-axis) with a force of 82.0 N, to the left with a force of 115 N, upward with a force of 565 N, and downward with a force of 236 N. Find the magnitude and direction of the net force on the crate. ---> I'm a bit confused about net...

Homework Statement angle is in relation to horizontal Homework Equations f net=m*a The Attempt at a Solution yikes! i don't know! i appreciate ANY help!

Homework Statement Each ball weighs 3.00 kg A is 10cm from C to the left and B is 40cm to the right of A Homework Equations F=Gm1m2/r^2 The Attempt at a Solution ive tried adding the forces that each ball apply to A and subtracting it. i know each has its own force acting on A...

Homework Statement (a) A box is placed on an frictionless inclined plane with an angle of 18° from the horizontal. The box has a mass of 35 kg, what is the magnitude of the acceleration of the box along the inclined plane? (b) What magnitude of force would you need to apply to the box in...

Homework Statement A 2.75 kg object is moving in a plane, with its x and y coordinates given by x = 7t^2 - 4 and y = 5t^3 + 1, where x and y are in meters and t is in seconds. Find the magnitude of the net force acting on this object at t = 2.35 s. Homework Equations F=ma The...

1. A ball is flying through the air, and at a given point in the flight, the ball is submitted to a gravitational force: F(g) = 1,5 N [downwards] and air resistance: F(air) = 0,50 N [32° above the horizontal]. Calculate the net force on the ball. 2. F (nette) = m x a 3. I thought I...

Homework Statement A small box is moved from position x1 to x2 by a net force which varies with position. On a graph, I plot the net force on the box vs. its position. The area in between the force curve and the x-axis is ...... And I am not sure if it is the work done on the box or may be...

The 'net force' in the statements below is the sum of ALL forces acting on the body. During the collision of a car with a locomotive, the locomotive exerts an equal size force on the car as the car exerts on the locomotive. False If an object's speed does not change, no net force is...

Homework Statement A model airplane has a momentum given by [(0.25 kg . m/s^3)t^2 - (0.75 kg . m/s^2)t]\hat{i} a.) What are the x- , y- , and z- components of the net force on the airplane? b.) At what time t is the x-component of the net force on the airplane equal to zero? Homework...

Homework Statement A ball is tossed up into the air. It reaches maximum height and comes back down. What is the net force on the ball at the following situations: a. The ball is moving upward as it is released. b. The ball is at it's highest point. (when it comes to a stop i suppose)...

Homework Statement Two forces, F1 and F2, act on the 7.00-kg block shown in the drawing. The magnitudes of the forces are F1=65.9 N and F2=22.7 N. Take the positive direction to be to the right. Find the horizontal acceleration of the block, including sign...

Homework Statement The book I am using (Zwiebach on page 66) uses the expression dF_v = T_0 \frac{ \partial{y}}{\partial{x}} |_{x+dx} -T_0 \frac{ \partial{y}}{\partial{x}} |_{x} for the force on an infinitesimal length of string. We assume dy/dx is much less than 1. I am not sure how the...

Homework Statement The drawing shows three point charges fixed in place. The charge at the coordinate origin has a value of q1 = +9.00 µC; the other two have identical magnitudes, but opposite signs: q2 = -5.00 µC and q3 = +5.00 µC. For the problem imagine the x-y coordinate grid with a +...

Take q1=25uC at (0,1), q2=20uC. at (2,0), and q3=? at (2,2). IF the force on q1 points in the -x direction, (a) what is q3 and (b) what is the magnitude of the force on q1? F=k(q1,q2)/r^2 coulombs law I know since q1 points in the -x direction that q3=q2. So (a)=20uC. I'm not sure...

Homework Statement Four charges, Aq, Bq, Cq, and Dq (where q = 3.50 ×10−7 C), sit in a plane at the corners of a square whose sides have length d = 23.5 cm, as shown in the diagram below. A charge, Eq, is placed at the origin at the center of the square. (Note that A, B, C, D, and E are...

Homework Statement In a velocity selector E and B fields are perpendicular. Which of the following conditions on the direction of the particle's velocity can result in no net force assuming the E and B are nonzero? Homework Equations F = Eq + q(vxB) The Attempt at a Solution The...

1. for fluids,why is the specific heat capacity at constan pressure is greater than that at constant volume 2. Can some one explain me about the use of air as an insulator in windows, they say it is coz of its low conductivity, how? 3. I've a got confusions about the word " net" that...

Homework Statement Charge 8e-18 C is on the y-axis a distance 2 m from the origin and charge 9e-18 C is on the x-axis a distance d from the origin. The Coulomb constant is 8.98755e9 Nm^2/C^2. What is the value of d for which the x component of the force on 9e-18 C is the greatest...

Homework Statement At what distance from the Earth should an astronaut be placed so that he will feel no net force when the Earth and the Moon and he are aligned? Homework Equations Fnet=ma F=(Gm1m2)/d^2 The Attempt at a Solution I assume I'm going to do a force annalysis, I'm...

The net force on a moving positive charge... Homework Statement A magnetic field has a magnitude of 1.2 x10^-3 T, and an electric field has a magnitude of 5.4 x10^3 N/C. Both fields point in the same direction. A positive 1.8 µC charge moves at a speed of 2.9x10^6 m/s in a direction that is...

Net Force in a DNA molecule?? Homework Statement The two strands of the helix-shaped DNA molecule are held together by electrostatic forces as shown in Fig. 16-44. Assume that the net average charge (due to electron sharing) indicated on H and N atoms is 0.2e and on the indicated C and O...