A pictorial device which analyzes forces present on any body with the use of vectors. Allows easier grasping of problems involving either objects at equilibrium or in motion. Can be used to predict presence of forces.

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What is total force in this context?

One site said the total forces is the sum of the vectors. My homework question is "A skydiver of mass 90 kg is falling with a terminal speed of 60 ms-1. What does that mean? What is the total force ...
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0answers
24 views

The athlete feels a centrifugal force when whirling the hammer - is there always a centrifugal force associated with a centripetal force? [closed]

(this is a homework question) To this, I would say that the centrifugal force is just the reactionary force of the centripetal force, which is causing the hammer to 'want' to move away. Therefore, ...
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22 views

Determining the direction of friction of a pole leaning on a block [closed]

This is the problem, can someone help me answer the item 7.40 thanks. The answer I get for the block to tip is 288 but the book said 353, how do you get 353?
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1answer
74 views

Solve hanging rope question by using Lagrangian density [closed]

for this one, I can only do the first(a) $$V_{total}=\frac{mg}{l} \int_{x_0}^{d-x_0}{y(x)\sqrt{1+(\frac{dy(x)}{dx})^2}}dx$$ and have no idea about others.
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1answer
34 views

Force Keeping Water Skier Afloat

A motionless water skier sinks because the upward buoyancy force on the skier is less than the downward force of gravity on the skier. A skier pulled by a boat does not sink into the water. Why?
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38 views

Force needed to hold a book between your hands - not sure about the influence of friction

I'm looking at this problem: A student presses a book between his hands, as the drawing indicates. The forces that he exerts on the front and back covers of the book are perpendicular to the ...
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2answers
48 views

Free body diagram of this system and equation

I'm studying physics but in this question I can't figure out the free body diagram. link: http://prntscr.com/6j0t2u For $m_3$: $$T-m_3 g = m_3a $$ For $m_2$ along the y-axis: $$N - (m_2 + ...
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2answers
64 views

Maximum acceleration uphill of a truck - not sure what the equations mean

I'm trying to solve a problem that reads: The coefficient of static friction between a truck's tires and the road is 0.850. What is the maximum acceleration uphill that the truck can have if the ...
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2answers
68 views

If an object rests on a table, not accelerating, how much work do both the object and the table do?

Obviously, the net work done is zero, because there's no motion, but is the proper way to look at it that both the object's gravity and the table's normal force do zero work, or that one does positive ...
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2answers
58 views

Question about circular motion of car turning

When we move round a roundabout there is a frictional force between the tires and the road that acts towards the centre of the roundabout in order to produce the circular motion. Why then do we ...
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26 views

Forces acting on an SHM

I would like to know the forces acting on an SHM, and how they effect the motion. For example, take the motion of a simple pendulum as in the given image. Which are the forces acting on this motion? ...
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48 views

Can $F=ma$ be used to calculate ground reaction force of someone walking/running?

Can Newton's second law of motion $F=ma$ be used to calculate ground reaction force of someone walking/running?
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40 views

What force acts on a coin that has been tossed when it is half way to the top? and what force acts on it when it is at the top?

This is a homework question and it appears to be a misleading question. I think that the answer is gravity for both of them. The only alternative answer I have is kinetic energy half way up and ...
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3answers
82 views

Forces on a ball thrown upwards

When a ball is thrown up in upward direction, it is said that force is in downward direction. Why we don't we consider the force given to the ball to throw up in the upward direction? Is there is no ...
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2answers
67 views

Is my answer possible? (Newtonian Third Law Pairs and Forces, Multiple Choice Word Problem)

So I recently took a test and the teacher graded my answer correct, yet my friends saw that the other answer was correct and they protest that it should be the right answer: The question goes: ...
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3answers
72 views

Tension Problem: Finding an angle when only given the tension in two ropes [closed]

A crate is hanging from a rope which is attached to a metal ring through which a second rope runs, as shown to the right. What is the angle $\theta$ if the tension in rope 1 is $1.19$ times the ...
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2answers
56 views

What are the forces acting when we squeeze a ball? Free Body Diagram?

As part of my project, I am trying to figure out the forces acting while squeezing a ball. The ball in question is a foam rubber ball (stress ball). The ball deforms when we squeeze & the mode of ...
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2answers
82 views

What does the force mean in $dp/dt$ form?

One was to write Newton's laws is: $$F=\frac{dp}{dt}.$$ I don't understand what is the force there. I believe that $F$ is the net external force on the system. So supposedly I have a mass which is ...
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5answers
140 views

Why am I not accelerated by the reaction force applied by Earth on me? [duplicate]

Newton's third law says that "to every action, there is always an equal but opposite reaction". And Newton's second law of motion says that, $F=ma$ $=>$ $a=\frac{F}{m}$. People says that If I stand ...
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2answers
28 views

If the force of friction is 20 N for a moving body does acceleration increase with the increase of the mass?

A body is moving and the only force acting on it is the force of friction. If we put another body on this moving body somehow the force of friction will increase; does its acceleration change?
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61 views

Can two bodies move with equal acceleration if forces acting on both are unequal?

In my textbook there is a case given that is to find acceleration and tension produced in a string passed over a frictionless pulley and attached with bodies of different masses at its ends. Now below ...
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1answer
29 views

Can two bodies of different mass attached at ends of string passed over a frictionless pulley produce equal tension on both sides?

In my textbook there is given a case that to calculate acceleration and tension produced in string when string is attached at it's ends with two bodies of masses such that $m1>m2$ and the tension ...
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1answer
21 views

Force of tension on both sides of one string- 2 questions

Here's something I want to ask you guys about: Many times downward N1 and N2 are ignored in exercises. Why? If forces of tension are balanced by each other, why won't objects just fall? Cheers ...
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1answer
47 views

When do we assume that a rope has different tensions in different places?

Working a problem with 2 pulleys and masses in class this week the professor at one point assumed that the tension on the two sides of a pulley would be different. Every other time we've done a ...
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71 views

A simple pendulum

The idealized simple pendulum model (see the following figure) assumes that at every point of time the string to which the bob is attached exerts an equal and opposite force on the bob as does the ...
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52 views

Direction of friction vector when acceleration is zero

There is a box on a ramp, there is Wx that makes it fall, Tension that pulls it up the ramp (a rope) and Friction. The thing is, how can I determine the direction of the friction? For me, friction ...
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1answer
61 views

How to draw the free body diagram of this? [closed]

There is a smooth light peg at C. The system is in equilibrium. The ground is rough. How do I draw the free body diagram for this? Here is the system, and my attempt.
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1answer
68 views

Is the force experienced by a particle influenced by its distance to the focus of the force? [closed]

Is the force experienced by a particle influenced by its distance to the focus of the force?
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2answers
152 views

Calculating Net Force with Free Body Diagram

Question: Three forces are acting on a 4-kg block. The acceleration of the block is 5.0 $m/s^2$. Find the magnitude of the unknown force $F$. The diagram I have shows the force F point left, a force ...
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1answer
55 views

Newton's 2nd and 3rd Law clarification [duplicate]

Hi I have a quick question. I know this may be a common question. If N3L states that there's an equal and opposite force, why do things still move? I have read up a lot and this is my understanding. ...
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3answers
73 views

Reason for motion after terminal velocity

Let some object hang by a string. So no motion since weight was counter balanced no net force. Now string is cut. Object is falling under gravity and experiences air resistance. Terminal velocity is ...
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1answer
47 views

Why we can omit some forces while applying linear momentum principle

While applying linear momentum principle, namely that if force is zero linear momentum of the system is constant, in textbook they don't count for $N$ force from $M \to m.$ This force have component ...
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1answer
84 views

Why doesn't a parachutist, according to Newton, “fall” upwards (because drag is larger than gravity)?

Part of the second law states that an object will accelerate in the direction of the unbalanced force. However, I've been thinking about parachuting and skydiving a bit lately, and I know that when ...
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2answers
143 views

When is tension constant in a rope?

Suppose we have a massless rope with pulling forces applied at each end. In which scenarios is the tension in the rope constant throughout? For example if there is a knot in the rope the tension is ...
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0answers
50 views

Can someone please explain the forces acting on the rod? [closed]

Can someone please explain the forces acting on the rod.
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0answers
17 views

Argument for stability of journal bearing via inertial and viscous forces?

As I understand a journal bearing, a rotor is levitated by hydraulic forces from the lubricant. While these are lots of studies on this subject, I can't manage to find a paper that coherently breaks ...
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2answers
99 views

What are the forces acting on a Pendulum Tuned Mass Damper?

Upon researching tuned mass dampers, I came across this free body diagram of a pendulum tuned mass damper. However, I don't understand where many of the forces come from. What exactly are the forces ...
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5answers
116 views

Relation between potential energy and forces

Can you also explain why can't we define potential energy corresponding to a non-conservative internal force? Non-conservative forces are those which don't depend on the initial and final states but ...
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0answers
48 views

Suspended mass in motion free-body diagram [closed]

A 20kg mass is held by two ropes which span 90 from each other. The mass is being accelerated at 1m/s^2 to the right. Draw a free body diagram for the mass and find the numerical values for each ...
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1answer
41 views

Maximum velocity on Unbanked roads and why should friction be more than centripetal force? [closed]

Why is maximum velocity on unbanked circular road given by $\sqrt{urg}$ where $u$ is coefficient of friction, $r$ is radius of circular track and $g$ is acceleration due to gravity? Why should ...
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2answers
241 views

Why do you have less control over a bicycle with a broader steer?

I recently had an argument with someone on why a bicycle with a broader steer gives you more control. We both had different answers to this question and neither could convince the other. First a ...
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3answers
174 views

Where does the force to stop a constant velocity object come from?

If a ball hits a wall at a constant velocity, it will slow down and eventually come to rest. Since the ball was at constant velocity, it was not accelerating, and so there was no force. Also, the ...
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4answers
739 views

Why doesn't centrifugal force appear on an FBD for a car on a banked track?

Suppose you wish to find the max speed at which a car can travel on a banked curve of radius R and angle theta to the horizontal and coeff. of static friction mu. I don't understand the relevant ...
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1answer
275 views

The direction of frictional force in smooth rolling motion

I want to ask about the direction of frictional force in smooth rolling motion which means the rolling object doesn't slide on the surface. Here is the first case, the wheel rolls to the right so the ...
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2answers
95 views

Work and Free Body Diagrams

I am a bit confused with how to find work when there is a free body diagram. I am trying to work out this problem, and in it a box is being pulled at a constant speed by a rope at a constant angle ...
2
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1answer
86 views

Cart and Fan Problem [closed]

I have this problem : A 2.19-kg cart on a long, level, low-friction track is heading for a small electric fan at 0.21m/s . The fan, which was initially off, is turned on. As the fan speeds up, the ...
3
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3answers
940 views

Tension of rope. Different Answers?

The tension of a rope in a tug of war with unequal forces is equal to the least force on the rope. Am I right? (If group A pulls the wire with 20 newton leftwards and the group B pulls with 30 newton. ...
2
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2answers
92 views

Force balancing - Newtonian mechanics [duplicate]

If a horse pulls the carriage, the carriage should pull the horse with equal force (Newton's third law), then how does the whole system move? I drew the free body diagram but not yet figured what ...
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1answer
83 views

Work energy and laws of motion and friction problem?

I am having a confusion in the following question- Q-To stimulate car accidents auto manufacturers study the collision of moving cars with mounted springs of different spring constants. consider a ...
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2answers
252 views

For a massless pulley moving upwards with acceleration, is the upward force equal to the downward force?

Imagine a massless and frictionless pulley with two weights hanging either side of the pulley by a massless string. Like this except not attached to a ceiling Rather than being fixed to a ceiling, ...