# Tag Info

### Different Bernoulli equation from $F=dp/dt$

It is better to work with small elements and later take the limit. $$\Delta p=\rho A_1\Delta x(v_2−v_1) \implies \frac{\Delta p}{\Delta t} = \rho A_1\frac{\Delta x}{\Delta t}(v_2−v_1)$$ The average ...
1 vote

### Different Bernoulli equation from $F=dp/dt$

Thank you to whoever telepathically answered my question. The answer can be found by asking yourself what happens if there is a piston pushing in the opposite direction on the volume of smaller cross ...

### Field of Inertial Forces

One way to arrive at what you suggest is to introduce the assumption that the phenomenon of inertia is mediated by a field. In terms of newtonian mechanics you would then have two fields with a common ...

### Field of Inertial Forces

Inertial forces behave like any other force apart from not deriving from an interaction with other bodies. In particular, the inertial forces that depend on the position may define a vector field. ...
1 vote

### The Work-Energy Theorem in Non-Inertial Frames: A Critical Analysis and Misconceptions

You can solve the problem by working in a non-inertial frame, but it is important to later calculate the velocities in the "ground" frame to determine the change in kinetic energy in this ...
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### Do chargeable batteries break the third law of newton?

Assume that electrons are at rest inside a battery. Or if they move, they do so equally in all directions, so the net momentum is $0$. Also assume that they leave one battery terminal with some ...

### Newton's second law - local laws and non-local laws

I will give you two examples. First a local law and then a non-local law, explaining each with examples to make it much simpler. Ok Local laws, such as Newton's second law for a car, tell you how fast ...

### Is the sectioning in method of sections, for truss analysis, arbitrary?

Yes. Since the sum of forces of any section of the trust must be zero, the net torque produced is going to be constant, moving from one location to another.

### Difference between Pulling a string and hanging a weight in an Atwood machine

If you are taking gravity to be 10m/s^2, there is no difference.

1 vote

### Will a radioactive ball conserve its angular velocity?

A sphere in vacuum ... should spin forever because of angular momentum conservation. However, assume that the sphere is made of radioactive material, or that its material is emitting radiation like ...

### About constant velocity linear motion with zero net force

I think your question is very interesting and important. Perhaps many people would misunderstand the difference between intertia motion and intertia coordinate/frame. As you mention, even though the ...

### How does gravitational potential energy work in a very large distance?

But when we change the direction of the asteroid slightly towards the planet, we create a situation where the mechanical energy becomes very large and negative Why do you think this? The total ...
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### How does gravitational potential energy work in a very large distance?

My answer I understand that there is still some gravitational potential energy between the asteroid and the planet even when they are very far apart, but it is very close to zero. So, the short ...

### How does gravitational potential energy work in a very large distance?

The gravitational potential energy is stored in the asteroid and planet system. Turning the asteroid round makes absolutely no difference to the gravitational potential energy stored by the system as ...

### Car rolling away on an Inclined Plane with friction

This may help! Take the example of a motorbike (2 wheels) and a car (4 wheels). At equal gear torque, both have the same acceleration. This implies that the no. of wheels does not affect the ...

### Why do rolling disc (coin) move in circular path?

$\vec{f_{1}}$ does not create a torque to cancel the weight's torque. Torque is $F\times r$, all torques have to be calculated w. respect to same point. If weight's torque was calculated w. respect to ...

### What really determines punching force?

As far as the physics is concerned, the real damage is caused by the impulsive force during the collision. If you deliver a punch with a huge velocity and the impact lasts for a short period of time, ...

### Friction & Normal Reaction

You should realize that there is no complete microscopic understanding of friction. And I am inclined to think that there is no universal answer to your question that would hold in general. This being ...

### What really determines punching force?

as a Kinesiologist my non physicist take on this question relates to the neuromuscular connections that contribute to power. The question is of efficiency of force generation rather than force as an ...
1 vote
Accepted

### Expression for Potential energy of a hanging mass

Potential energy is never an absolute value - it is always measured relative to some base configuration or point that is assigned zero potential energy. And the location of this base point is ...
1 vote

### Expression for Potential energy of a hanging mass

Because you need to choose a reference frame. It's not mandatory to choose the origin at the level of the ground, it's possible to choose the origin wherever you want but you must be consistent with ...
1 vote

### Do conservative forces obey Newton's laws of motion? If we look closely, non-conservative forces like Friction etc follow 2nd law but Im confused

Newton's second law states that the net force acting on an object equals its change in momentum. The net force can be any combination of conservative and non-conservative forces. The difference ...

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