# Tag Info

### 2 objects heading towards each other at a certain distance and with initial velocity and friction coefficient

Depending on the mass of both A and B (assuming the friction is caused by a gravitational force), the answer will change.

### Does the acceleration formula from dynamics apply in all cases?

Acceleration is total external force divided by mass provided the object in question can be treated as a point mass with a single acceleration and it is not moving so fast that relativistic ...

### Why does a plastic bag rip when it is raised to a higher position when being held but not when it is stationary?

You move the bag upwards with an acceleration. If you were to pull the bag up with infinitesimal acceleration, it would not rip then, because the force required for that would approach zero. But since ...

### Why does a plastic bag rip when it is raised to a higher position when being held but not when it is stationary?

This is like holding a weight $mg$ with a string which can break with a tension of $1.1 mg$. When you are not moving the bag, or moving it at a uniform speed, the string's tension is constant at $mg$,...

### Centripetal Force Formula Confusion

You are trying to think of the force in terms of radius, whereas the force required depends upon both the radius and the linear velocity V or angular velocity. Try to think about how much minimum ...

### Force as a Function of Position

dont make things so complicated: m(dv/dt)=F...then multiple both sides by v(dt), we get mv(dv)=Fv(dt)...because vdt=dx....then mv(dv)=F(x^0)(dx)...intergrate...and you find K.E.=P.E., or force as a ...

### Vertical component of moving weight at a 45 degree angle

While the technically correct answer is W × sin(45), practically I think the ratio is closer to 0.5-0.6. Due to the balance necessary in an unbraced squat with a ...

### What is the constant in $F=kma$ called?

Closest analog to your expression would be relativistic Newton second law : $$F = \gamma ma \tag 1,$$ where $$\gamma = \frac{1}{\sqrt{1-\frac{v^2}{c^2}}} \tag 2$$ is called Lorentz factor, but it's ...

### Direction of undetermined contact force & undetermined Normal force

In a situation where two corners are in contact, the contact force (acting on the blue part below) can be in any direction (and magnitude) and thus can be decomposed into two components. In a ...

### Bar suspended by three vertical ropes

This is a canonical example of an underdefined problem (the number of unknowns (3 tensions) is less than the number of conditions (torque=0 and total force=0). You've tried to come up with a third ...

### How does friction applied to a rolling sphere in 3 dimensional space

The plane is described with u , v parameter and the trajectory on the plane with s parameter . Thus the position vector to the contact point is $$\vec R=[x(u(s),v(s)), y (u(s),v(s)),z (u(s),v(s))]^T$$...

### Rotational Equilibrium With Forces acting on only two points

The rod cannot achieve rotational equilibrium. Your thinking is right. The rod will have to rotate about the hinge because of the torque due to its weight. mgsinθL/2 = Iα

### Why can multiple eggs support more weight per egg when there are more of them?

Because the pressure changes and the weight is distributed to each egg.What causes fracture or any other plastic deformation is pressure not force. Pressure $P$ is related to force $F$ by this formula:...

### Can two electrons attract each other?

We are currently exploring a hypothesis that suggests two electrons can exhibit attractive forces under certain conditions, specifically when considering their magnetic dipole moments and specific ...
Accepted

### Why can multiple eggs support more weight per egg when there are more of them?

With a fracture process the fracturing is usually caused by a local concentration of stress, that is there is some small region where a lot of force is concentrated in a small area and the resulting ...
1 vote

### If an object suspended by a string is immersed in a liquid, will its weight contribute to the pressure at the bottom of the container?

Assuming the set-up is in equilibrium, and that the atmospheric pressure is zero, the tension in the string would balance the apparent weight of the sphere (the apparent weight being mg-buoyant force)....
Accepted

### Where does the reaction force go when we slip?

However on a slippery plane when I walk forward, doesn't the plane also apply a force equal in magnitude and opposite in direction, hence making me move forward. Unless the plane is totally ...

### Where does the reaction force go when we slip?

I believe your question is the following: Your foot exerts a force on the surface and the surface hence responds with a friction reaction force as per Newton's 3rd law. On the slippery surface, your ...
1 vote

### Where does the reaction force go when we slip?

Force occurs in pairs, i.e action and reaction are simultaneous. When you push the ground, the ground simultaneously exerts a reaction force. This reaction force does not depend on friction. Now, ...

### Would one be pushing as much as their weight with this machine?

His arms move a longer distance than he is lifted. Therefore the force he needs to push with is lower than his weight. There is a mechanical advantage. Much like to lift the rock in this picture, the ...