Net force Definition and 496 Threads

A 4.0 x 101 kg wind sled is gliding East across a frozen lake at a constant speed of 12 m/s, when a gust of wind from the southwest exerts a constant force of 1.0 x 102 N on its sails for 3.0 s. With what velocity will the sled be moving after the wind has subsided?

Homework Statement Calculate the magnitude of the net force on an air parcel of mass 1.0x10-3kg which is at a temperature 250K and which is in the US standard atmosphere at an altitude of 4.0km. Take the lapse rate as 6.5K/km and the surface temperature as 288K Homework Equations Force =...

Suppose I have an object moving in a free space at initial velocity of v (no friction). Then two forces of equal magnitude but opposite directions are applied on the moving object of which one of them is in the same direction as the moving object. Is there work done by that force?

Homework Statement Three parallel wires carry a current of I 1 = 3 A, I 2 = 2 A, and I 3 = 1 A, respectively. They are arranged as shown. If r = 2m and L=5m,what is the magnitude of the net force on the bottom wire? <------------------------- I1 r -------------------------->I2 2r...

Work is defined as force times displacement. When the force is applied on an object which does not move, or is applied perpendicular to the direction of motion, the work done is zero. So let's say I hold an object with a mass of 1 kg still in the air for 10 seconds. Because the object does...

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.

Why does a body accelerate when it experiences a net force? Is there any change in molecular state of the body when it experiences a force?

Homework Statement 13 equal charges are placed in the corners of a regular 13-sided polygon. What is the force on a test chrage at the center? Homework Equations principle of superposition symmetry The Attempt at a Solution I am not sure if the net force is 0 or not. Had the polygon...

First time in these forums so nice to meet everyone Homework Statement A dynamics cart is pulled from rest by a net force of 1.2M [Forward]. The cart moves 6.6m, reaching a velocity of 3.2m/s [Forward]. Homework Equations F=ma The Attempt at a Solution I tried using the...

Hi all, I have a conceptual question about the net force of a rotating or spinning ball attached to a string. If we have a situation such as a tether-ball game where the ball is being swung around a string at an angle to the vertical, is the net force the tension in the string, or the...

Homework Statement A charge of +2q is placed at the origin and a second charge of -q is placed a x = 3cm. Where can a third charge +Q be placed so that it experiences a zero force? Homework Equations F=kQ1Q2/r^2 The Attempt at a Solution OK I thought I had this until the roots of...

How would I find the net force given the angle of the applied force, the mass, and the magnitude of the force? Homework Equations F=ma I need to fit an angle in that equation somehow.

Homework Statement An object is being swung vertically on a stick. What is the net force at the bottom? The mass of the object = 2kg. g= 9.81ms-1. v = 6ms-1 at the bottom. Homework Equations F= mg Fcentripetal = (m*v^2)/r The Attempt at a Solution I just need to know if i...

Net force (Diagrams incl) Please check my solutions :) Homework Statement Calculate the net force acting on each object indicated in the following diagrams. Show your work. The diagrams are in attachment, you don't have to download them to view them :) Homework Equations...

Homework Statement • If we add a third block, leaving the 10 N force the same, what happens to f3, the net force on the 3 kg block? A. Increase B. Decrease C. Stay the Same D. Not Enough Info. Homework Equations F net = m * a The Attempt at a Solution Ignore the...

Question is: A mother weighing 58.2kg is holding onto the hand of her daughter who weighs 35.5kg. If the father grabs the hand of the mother and pulls with a force of 100N, how much net force does the daughter experience? Iv'e been looking through my Physics formula and can't even find...

Homework Statement A particle is moving along the x-axis subject to the potential energy function U(x) = 1/x + x2 + x - 1. Determine the x-component of the net force on the particle at the coordinate x= 3.29m. Homework Equations U(x) = integral(F(x)dx) The Attempt at a Solution...

Homework Statement You have to calculate the net force acting on a wagon that is being pulled by two separate forces. Roping being pulled: 12N /32° |-----------------| / | |------------ |-----------------| \...

Homework Statement http://imageshack.us/photo/my-images/534/jillo.jpg/ Okay, so I was given a diagram that looks like the one I linked to above. This is pretty basic, using Newton's second law to find- A) the weight of the "lamp" B) the tension in the chain The strut is exerting a...

Homework Statement In a region of two-dimensional space, there are three fixed charges: +1 mC at (0, 0), -2 mC at (16 mm, -6 mm), and +3 mC at (-6 mm, 20 mm). What is the net force on the -2-mC charge? -magnitude -direction (° counterclockwise from the +x-axis) Homework Equations F =...

Homework Statement Three positive particles of equal charge, +11.5 µC, are located at the corners of an equilateral triangle of side d = 13.0 cm (Fig. 16-50). Calculate the magnitude and direction of the net force on each particle. Image is here...

Homework Statement In a region of two-dimensional space, there are three fixed charges: +1 mC at (0, 0), −2 mC at (12 mm, -7 mm), and +3 mC at (-6 mm, 18 mm). What is the net force on the −2-mC charge? magnitude direction ° counterclockwise from the +x-axis Homework Equations...

Homework Statement A charge, Q2 = -7.00x10^-6 C, is 8.00 cm to the right of charge Q1 = 6.00x10^-6 C. Where can a third charge be placed, along the line connecting Q1 and Q2, such that it experiences no net force? Give distances relative to Q1 and use a plus sign if the third charge is to the...

Homework Statement One charge of (+5µC) is placed in the air at exactly x = 0, and a second charge (+7µC) at x = 100cm. where can the third charge be placed so as to experience zero net force due to the other charges? Homework Equations F=KQ1Q2 / D^2 The Attempt at a Solution Q1 =...

Homework Statement Four objects, each with a positive charge of 1.0 3 1025 C, are placed at the corners of a 45° rhombus with sides of length 1.0 m, as in Figure 13. Calculate the magnitude of the net force on each charge. Homework Equations F = Kq1q2/r^2 The Attempt at a Solution

Homework Statement I am trying to help a friends daughter understand her physics homework. We have been stumped for hours! We don't really understand what her teacher was talking about and what we have figured out has mostly come from google. The problem is (this is drawn out no real...

Need to find the net force and the average force... 1. Homework Statement A bullet of mass 12 g strikes a stationary fixed block of wood at a speed of 400m/s, penetrating to a depth of 3.0cm. Calculate the average net force acting on the bullet while it is in the wood. Calculate the average...

Homework Statement Two charges, q1 and q2, are separated by a distance r. Find the position at which a third charge, q3, can be placed so that the net electrostatic force on it is zero. Homework Equations Coulomb's Law: F = (kq1q2)/r122 * (r12hat) The Attempt at a Solution I was...

A bullet of mass 20 g strickes a fixed block of wood at a speed of 320m/s. The embeds itself into the block of wood, penetrating to a depth of 6.0cm. Calculate the average net force acting on the bullet while it is being brought to rest.

Homework Statement A small ball of mass m = 0.150 kg is sliding along a frictionless loop-the-loop. The loop-the-loop is standing on a table such that the plane of the loop is vertical. The loop has a radius of r = 0.200 m. What is the magnitude of the net force acting on the ball when it...

Homework Statement If wind blows at 35m/s over a house, what is the net force on the roof if its area is 240m^2 and is flat? Homework Equations P=F/A and P1 + 1/2pv^2 = constant The Attempt at a Solution I have no idea on how to find pressure, because if I sub it into P1 + 1/2pv^2 =...

Homework Statement Block C (m = 4 kg) sits on a frictionless horizontal surface. Block B (of m = 2 kg) sits on top of block C, and is attached to a rope that runs over the massless pulley as shown in the figure. Block A (m = 1 kg) hangs vertically from the rope. With what horizontal force...

how can it be that the net force exerted on the mass m2 be zero?

Homework Statement A car rounds a curve while maintaining a constant speed. Is there a net force on the car as it rounds the curve? Homework Equations none-concept question The Attempt at a Solution yes... centripetal force?

Homework Statement A stalled car is being pushed up a hill by 3 people and it is moving at a constant speed the net forcce on the car is a in the opposite of the cars motion b in the same direction as the cars motion-wrong c zero d none of the above Homework Equations noone The...

Homework Statement The coefficient of static friction between a block and a horizontal floor is 0.40, while the coefficient of kinetic friction is 0.15. The mass of the block is 5.0 kg. If a horizontal force is slowly increased until it is barely enough to make the block start moving, what is...

Homework Statement A ferris wheel at a carnival has a radius of 12 m and turns so that the speed of the riders is 8m/s a) what is the magnitude of the centripetal acceleration of the riders? b) what is the magnitude of the net force required to produce this centripetal acceleration for a...

Homework Statement An advertisement claims that a particular automobile can "stop on a dime". What net force would actually be necessary to stop an automobile of mass 850 kg traveling initially at a speed of 51.0 km/h in a distance equal to the diameter of a dime, which is 1.8 cm? Answer...

Homework Statement A flea jumps by exerting a force of 1.20 X 10-5 N straight down on the ground. A breeze blowing on the flea parallel to the ground exerts a force of 0.500 X 10-6 N on the flea. Find the direction and magnitude of the acceleration of the flea if its mass is 6.00 X 10-7 kg...

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...

Homework Statement Find the net force of 3.4 N i + 3.0 N j and 3.4 N i + -3.0 N j I entered 6.8 N i + 0 N j, It's marking 6.8 as incorrect. Why? Do you not just sum the components??

Homework Statement Three point charges are arranged as shown in the figure below. (Take q1 = 5.70 nC, q2 = 4.60 nC, and q3 = -2.79 nC.) (a) Find the magnitude of the electric force on the particle at the origin. (b) Find the direction of the electric force on the particle at the...

Homework Statement A rectangular loop wire is placed next to a straight wire, as shown in the figure. There is a current of 3.5 A in both wire. Figure: http://www.flickr.com/photos/65980314@N06/6020832477/ Homework Equations F = ((mu(0)*I1*I2) / (2*pi*r)) * L force in terms of...

In a supermarket parking lot, an employee is pushing ten empty shopping carts, lined up in a straight line. The acceleration of the carts is 0.05 m/s^2. The ground is level, and each cart has a mass of 26 kg. a. What is the net force acting on anyone of the carts? b. Assuming friction is...

Some of the following is more or less Halliday & Resnick, 4th Ed., section 9.8 (not the whole section and I added a lot): Assume motion in a stright line. Therefore, for position, velocity, acceleratiom, force, momentum, etc., d/dt|vector|=|d/dt(vector)|. This is not true in general for...

Homework Statement In a region of two-dimensional space, there are three fixed charges: +1 mC at (0, 0), −2 mC at (15 mm, -2 mm), and +3 mC at (-5 mm, 15 mm). What is the net force on the −2-mC charge? ? magnitude ? direction ° counter-clockwise from...

Homework Statement "A 6.0 kg box is held at rest by two ropes that form 30-degree angles with the vertical. An external force F acts vertically downward on the box. The force exerted by each of the two ropes is denoted by T. . . . The magnitude of force F is 410 N. The magnitude of force T...

Homework Statement Two ropes are attached to a log that is floating in the water. A force of 80.0 N is applied to one rope and a force of 60.0 N is applied to the other rope, which is lying at an angle of 40° from the first rope. What is the net force on the log? We know that the angle...

Three blocks are bring accelerated upwards at 3.2m/s2, by a force applied to the bottom block as shown in the figure. The mass of the bottom block is 12kg, the mass of the middle block is 24 kg, and the top block is 36 kg. What is the net force on the top block? a.44.8 N b.67.2 N c.115.2 N...

Homework Statement A long, straight wire carries a current of 14A. Next to the wire is a square loop with sides 1.0m in length, as shown in the figure. The loop carries a current of 2.5A in the direction indicated. http://img69.imageshack.us/i/walker2260.jpg/ Calculate the magnitude of...