1. ### Net force acting on a charged particle ##+Q##

Homework Statement Twelve equal particles of charge ##+q## are equally spaced over a circumference (like the hours in a watch) of radius R. At the center of the circumference is a particle with charge ##+Q##. a) Describe the net force acting over ##+Q##. b) If the charge located at...
2. ### Which answer is correct? Grocery Bag Net Force Question

Today, my class had a dispute between who was right. Two answer keys for this problem was provided, so nobody knows the exact answer to this problem. Half of my class said 100 N while the others said 298 N or something. We won't talk about how I wasn't listening to that because I was trying to...
3. ### I How does a the vertical force of gravity end in horizontal motion?

When a stream of water falls perfectly vertical, some water hitting the surface will disperse horizontally. What is the force that causes this? References would be awesome!
4. B

### How to measure net force based on diagram

Could someone explain how to find the net force of an object based on a diagram. For example a 2 people walking with forces labeled weight force, reactant force, thrust and drag on one image all forces are balanced which I know the net force would be zero however on the second image thrust is...
5. A

### Finding net gravitational attractions in a triangle

1. The problem is attached in a picture. I've done it five times and keep getting it wrong. The correct answer is also displayed in the picture. Thank you for any help. 2. Fg=Gm_1m_2/r^2 3. I calculated Fg between AB and BC (they are equal). So Fg=(6.67*10^-11)(4)(4)/(.10)^2=1.067*10^-10...
6. ### Newton's Second law

Homework Statement The two forces F⃗ 1 and F⃗ 2 shown in (Figure 1) act on a 29.0-kg object on a frictionless tabletop. Suppose that F1 = 10.8 N , and F2 = 19 N . A. Determine the magnitude of the net force on the object for the diagram (a) in the figure. B.Determine the angle between the...
7. ### Statics -- Net Moment

Homework Statement Homework Equations I can see how the net force is not the same but I'm not getting the net moment. The Attempt at a Solution 12mm x 10N = 120N-mm. How do these two FBDs not have the same net moments. Thanks for any help!
8. ### Finding magnitude of tension that causes object to slip

Homework Statement A rope attached to a 19.0 kg wood sled pulls the sled up a 19.0° snow-covered hill. A 14.0 kg wood box rides on top of the sled. EDIT: the actual question to be answered, oops. What's the magnitude of the tension that will cause the box to slide? Mass of box (mb) = 14.0kg...
9. ### Where to place a third charge so it experiences no force

Homework Statement A point charge of 5.6 microcoulombs is placed at the origin (x=0) of a coordinate system, and another charge of -1.9 microcouloumbs is placed on the x axis at .29m. Where on the axis can a third charge be placed so that it experiences no charge? q1= 5.6 E-6 q2= -1.9 E-6 d=...
10. ### Acceleration of an object given forces

Homework Statement An 85 kg tobbogan that was originally accelerating at 3.0 m/s2 on frictionless snow hits a bare patch of concrete that exerts a force of friction on the sled of 180 N, what will the new acceleration be? Homework Equations F=ma The Attempt at a Solution Ok so this was...
11. ### Net force =0 or Net force =GM^2/4R^2....?

Two stars of equal mass M move with constant speed V in a circular orbital of radius R about their common center of mass .What is the net force on each star? the answer to this question was net force=GM^2/4R^2 .I want to ask that why net force not equal to zero although it is in translational...
12. ### Traction and a Broken Leg

Homework Statement An accident victim with a broken leg is being placed in traction. The patient wears a special boot with a pulley attached to the sole. The foot and boot together have a mass of m = 4.0 kg, and the doctor has decided to hang a 6.0 kg mass from the rope. The boot is held...
13. ### How to calculate net force

Homework Statement Calculate the net force on A.[/B] Homework Equations F=k . (q1 q2)/r^2 , k=9 x 10^9 Nm^2/C^2[/B] The Attempt at a Solution (9*10^9 Nm^2/C^2)(1,4 x 10^-6C)(7,2 x 10^-6C) / 1,7mm^2 = 0,0313. Could someone tell me what I am missing even if what i did is even correct...
14. ### Net Force and Direction of motion

Homework Statement Is the direction of net force always in the direction of motion? The Attempt at a Solution I would say no because the net force could be equal/balanced for example if two kids were pulling on a stick 2 N left <---- . ----->2 N right the Total Net Force would be 4 N...
15. ### Bobseld Forces Problem

Homework Statement In the men's four-man bobsled event in the winter olympics, the maximum mas of a bobsled with pilot, two riders, and a brakeman is 630 kg. During a practice run, the rear rider and the brakeman exert average forces of 1220N and 1200N [forward] respectively to accelerate a...
16. ### Force question

Homework Statement An object slides across a table at a constant 8.0 m/s to the right. The net force is... A) zero B) equal to the weight C) equal to the mass times the velocity D equal to the friction force Homework Equations N/A 3. The Attempt at a Solution Bu narrowing it down i don't...
17. ### First Year Physics Assignment - Theory

Homework Statement Answer true, false, or Cannot tell to teach of the five statements below. A) A 2 kg ball and a 3 kg ball are dropped from a tower. The net forces on each other are the same. B) An astronaut stands on a bathroom scale on the surface of the moon; the scale reads the astronaut's...
18. ### Static Equilibrium Question

Q: Why does the pin have a vertical force in this diagram (Static equilibrium)? The diagram depicts as follows: A mass (M) sits a a distance (d) away from the end of a board of length L. The board has a mass of m and is held to a wall by a pin and string. The string has a tension (T) and is at...
19. ### Momentum and net external force

Homework Statement In the picture Homework Equations In the picture attached. The Attempt at a Solution For the firecracker problem, I believe the only net external force is gravity. Therefore using, Fnet * delta t = delta p. Change in momentum is 12 kg * m/s. Thus, the final momentum of the...
20. ### Find missing force for accelerating electron

[Mentor's note: no template because this thread was moved into the homework forum after it had already attracted several useful replies] [Mentor's note: Thread title changed to reflect question content] The question is: An electron is a subatomic particle (m = 9.11 10-31 kg) that is subject to...
21. ### Interpret results of suspended mass / tension problem please

Homework Statement Two masses: m1 = 45 kg, m2 = 12kg. m1 (45kg) sits at rest on a table top with static friction co. 0.45, kinetic friction co. 0.35. m2 is suspended in the air. m2 is attached to m1 by a massless wire hung over a frictionless pulley Homework Equations FBDs, net force...
22. ### Truck pulling trailer

I have a truck (m1,27000 kg) pulling a trailer (m2, 8500 kg) with a chain holding the two together (T). The overall acceleration is 0.78 m/s^2. Find f1 force on the truck, f2 force on the trailer and T, tension force. Here is what I did: since the force comes all from the truck, f1 =...
23. ### Motor Principle and Magnet on Balance

Hi everybody. This is my first thread ever on this forum :S I'm in a first year physics class, and the other day we did a lab involving a c.c.c (current carrying conductor) and a magnet on a balance. The c.c.c was a wire which completed a circuit. One had a magnet assembly which was placed on...