Tagged Questions
4
votes
3answers
103 views
Moment of Inertia (triangular plate)
I want to generalize the formula for the MOI of a triangular plate (sides $a,b,c$) about an axis passing through mid point of one sides and perpendicular to it's plane .
The mass of plate $M$ is ...
0
votes
1answer
37 views
Period of oscilation [duplicate]
Two masses $m_1$ and $m_2$ are connected by a spring of spring constant $k$ and slide freely without friction along horizontal track. What is period of oscillation? No force influence.
4
votes
1answer
83 views
How did Newton find out force has something to do with acceleration?
Its about Newton's second law of motion,
$$F=ma.$$
It says the acceleration of an object is directly proportional to the net force and is inversely proportional to the object's mass. Yes I can ...
0
votes
3answers
70 views
Mass equals Moment of inertia when constant density?
I have found equation for moment of inertia $(J)$. I'm calculating $J$ for hemisphere, with rotational axis $Z$.
$$ J = \iiint\limits_V r^2 \cdot \rho \cdot dV $$
But if $\rho$ is constant ...
2
votes
1answer
66 views
Sitting on the bob of a pendulum
Walter Lewin's best performance was the pendulum demonstration, and I copy the transcript now:
Would the period come out to be the same or not?
[students respond]
Some of you think it's ...
0
votes
0answers
98 views
Spring with mass [closed]
A block of mass $M$ is attached to a spring that has mass $m$ and the force constant $k$. The block is placed on a horizontal frictionless surface. Find the period of small-amplitude oscillations ...
1
vote
1answer
89 views
Does mass concentration affect the torque induced by a force?
If you had two bodies with the same weight but one having mass concentrated more in the center, while the other had most mass concentrated on the outside, but both had the same center of mass and ...
-1
votes
1answer
146 views
What will happen when measuring unmeasurable object?
There is a set called Vitali Set which is not Lebesgue measurable.
Analogously, there also exists a Vitali set $Y$ in $\mathbb R^3$ which is a subset of $[0,1]^3$ and $|Y\cap q|=1$ for all $q\in ...
0
votes
1answer
922 views
Calculating Moment Of Inertia
The problem I am working on is:
A uniform, thin, solid door has height 2.10 m, width 0.835 m, and mass 24.0 kg.
(a) Find its moment of inertia for rotation on its hinges.
(b) Is any ...
0
votes
1answer
240 views
Mass points of a Mass-spring model
Let's say I have a mass spring model like the one in the picture below:
So, there are 3 parts of the spring joined together in an equilateral triangular manner. Each of the joints has a mass of ...
0
votes
3answers
92 views
Center Of Mass Troubles
I understand the concept of Center Of Mass(com), but I am having a difficult time interpreting the equation of the simplified case of one-dimension.
The book I am reading defines the position of the ...
1
vote
3answers
303 views
If something weighs 25 kg, how do I find the mass of the object?
An object is falling and it weighs 25 kg (on a scale, presumably). What is its mass?
I know that weight is measured in Newtons and mass in kilograms, but what if a problem states that something ...
13
votes
9answers
1k views
What is the difference between weight and mass?
My science teacher is always saying the words "weight of an object" and "mass of an object," but then my physics book (that I read on my own) tells me completely different definitions from the way ...
0
votes
2answers
210 views
Center of mass of a car
This might be little of the track but my question is more on possibility of application of principle of center of mass.
The probability of a vehicle overturning depends more on the level of center of ...
1
vote
1answer
138 views
Is $w=mg$ the right way to calculate mass?
How can you find the mass of an object by using a weight and a gravitational acceleration from another planet then earth? I was given $5.8\text{ N}$ and an acceleration of $4.0\ \mathrm{m/s^2}$. The ...
0
votes
2answers
719 views
Preventing a block from sliding on a frictionless inclined plane
I want to demonstrate what force $F$ you would have to exert on an inclined plane of angle $t$, mass $M$ to prevent a block on top of it with mass $m$ from sliding up or down the ramp. I worked out ...
2
votes
5answers
965 views
Why Gravity attracts all objects with the same speed?
Why Gravity attracts all objects with the same speed? Is this question was solved? What is the exact answer?
0
votes
0answers
166 views
Why Is Linear Inertia Only A Property? [closed]
The Inertia of a body is said to be its property or virtue that is directly proportional to its mass. Now if we consider Inertia of rectilinear motion, it depends on the mass as well as the ...
-2
votes
2answers
3k views
How exactly does mass affect speed?
I konw that mass affects weight (force), so how does that relate to speed? F=ma. so how does all this affect speed?
1
vote
3answers
108 views
Carrying water on person, or on the frame when bicycling
So, the question is as follows:
What is the difference in work exerted by the rider in the two following scenarios?
a) Rider + bike. Water carried in a holder on the frame
b) Rider + bike. Water ...
0
votes
3answers
919 views
Why is force described as rate of change of momentum?
momentum = mass * velocity
Differentiating both sides leads to
force = mass * acceleration
since the mass doesn't participate in the differentiation as it is constant.
Is this a sound ...
4
votes
3answers
419 views
Infinite acceleration?
Why is acceleration regulated by mass? In a frictionless environment, why doesn't an object move at infinite acceleration if force is applied on it?
Force causes movement, so unless there is an ...
1
vote
1answer
773 views
Can we determine the force an object exerts by its mass and acceleration?
I understand that the objects acceleration is determined by the force exerted on it, and that the force exerted on it is determined by its acceleration.
But, does an object's (named A) acceleration ...
2
votes
1answer
225 views
momentum conservation question involving a rocket and a spaceship [closed]
With the engines off a space ship is cruising at a velocity of 230m.s
It fires a rocket straight ahead at the enememy vessel. The mass of the rocket is 1300kg and the mas of the ship (not including ...
0
votes
1answer
792 views
Vertical component of moving weight at a 45 degree angle
Here's an easier one.
I use the leg press machine at the gym so I don't have to worrying about hurting myself while lifting heavier weight.
The weight glides on a track that looks to be 45 degrees.
...
