Questions tagged [acceleration]
The rate of change of velocity of a body per unit of time.
2,890
questions
0
votes
0
answers
42
views
Why is initial velocity 0 for retarding motion? [closed]
Issue details
Why retarding has initial velocity 0? It should be same as max speed of the previous motion of the body.
if you kindly look at this question: https://byjus.com/question-answer/a-car-...
- 101
0
votes
1
answer
30
views
In a fluid flow, how do you tell if negative acceleration is deceleration or change in direction?
When solving for the acceleration of a fluid flow, you use the equation: (∂u/∂t)+u(∂u/∂x)+v(∂u/∂y). If the solution at a given u and v are negative, how do you know if the flow has a negative ...
8
votes
2
answers
1k
views
In general relativity, why is Earth able to accelerate?
I was told and convinced that gravity is not a force, and in free fall you're an inertial frame and experience no force, and when on the surface of Earth you would be accelerating upwards.
What I ...
- 161
7
votes
2
answers
285
views
Power required to accelerate object [closed]
I am calculating power to accelerate an object of mass M in time T. My intuition tells me to calculate kinetic energy of the object and divide by T. Say a mass of 40 kg is accelerated from 0 m/s to 10 ...
- 71
1
vote
2
answers
58
views
Why we take $k=1$ in $F=ma$? [duplicate]
I know that $F$ is directly proportional to mass and acceleration but why in formula we take $k=1$ not other constant?
- 27
1
vote
0
answers
57
views
Acceleration $v = sin (100t^2+2)$.? [closed]
The relationship between the velocity of the top of a birds wings with time before takeoff is modelled by $v = sin (100t^2+2)$. What is the acceleration after 0.5 seconds?
Acceleration is the rate ...
- 31
0
votes
0
answers
20
views
Predicting position given constant angular + linear acceleration with a non-fixed axis
My readings on rotational motion always describes rotation around a fixed axis: that is, an object on a string, basically, and changes to angular velocity will alter speed such that the radius is ...
-3
votes
0
answers
23
views
I want to know the answer not sure if mine is correct [closed]
[][1 I want to know the answer not sure if mine is right I got 240N for the driving force 600000 joules for work and 800 for power
- 1
0
votes
1
answer
40
views
Does a rotating body resist acceleration in a direction that is perpendicular to the direction of the rotation of the body?
I would like to know if a rotating body resists acceleration in a direction that is perpendicular to the direction of the rotation of the body.
Say for example there is a bicycle wheel with a tire on ...
- 383
2
votes
1
answer
53
views
(Circular motion) Acceleration is given, so why asked for more? [closed]
The full question is below.
A car starts from rest and moves around a circular track of radius $32.0\,\text m$. Its speed increases at the constant rate of $0.500\,\text{m/s}^2$.
(a) What is the ...
- 21
10
votes
1
answer
2k
views
Antennas and relativity
Antennas work by accelerating electrons to emit EM radiation. In fact, my understanding is that any accelerating electron will emit EM radiation.
But in relativity, no frame of reference is preferred. ...
- 825
2
votes
2
answers
75
views
Are the definitions of force and acceleration circular? [duplicate]
Force is defined by acceleration , and acceleration requires the determination of" inertial frames".
But an inertial frames also requires the knowledge of forces which requires measuring ...
- 75
0
votes
0
answers
40
views
Physical and Diagrammatic representation of $a$=undefined when $v$=0 according to $a$=$vdv$/$dx$
$a$=acceleration
$v$=velocity
$x$=position along x axis
$t$=time instant
My teacher derived the $a$=$v$$dv$/$dx$ formula as follows
Assume a particle at time $t$ is at $x$ position having $v$ velocity
...
- 31
2
votes
3
answers
83
views
How to understand the larger than $g$ acceleration of the free end of a falling chain?
In this article I read that the acceleration of the free end of a falling folded chain is greater than $g$, but I cannot really understand why. Why isn´t the acceleration just $g$ since it is a free ...
- 119
3
votes
5
answers
155
views
What happens physically when object is thrown up when $v$ becomes 0 at max height?
When velocity=0 during maximum height when an object is thrown up, what does that actually mean?? does that actually mean that the object doesn't change it's position over dt time period when at ...
- 31
0
votes
2
answers
52
views
Why tangential acceleration become 0 when the velocity is max?
I Know that tangential acceleration equal to zero when the circular motion is uniform, but why it is equal to 0 , when the velocity is max or min , because there is no relation between the value of ...
- 11
0
votes
1
answer
60
views
Velocity and acceleration of a ball shot uphill [closed]
Consider a ramp of length $100$ m and with a height of $10$ m. At the base of that ramp we're shooting a ball of mass $12$ kg uphill. Let's say the ball has a speed of $1$ m/s at $1$ m uphill. How can ...
- 103
-2
votes
1
answer
62
views
What is $V$ in $a$=$V$$dv$/$dx$? [duplicate]
$a$=instantaneous acceleration
$V$=instantaneous velocity
$x$=position
$dx$=small Chang in position
$a$=$dv$/$dt$
multiplying numerator and denominator by $dx$,we get
$a$=$dv$.$dx$/$dx$.$dt$
now we ...
- 151
0
votes
2
answers
84
views
Is the sensation of falling purely due to air resistance?
When I jump off of something, even with eyes closed I can be pretty certain that I'm falling due to the associated sensation of falling. However, as gravity should be affecting each of my internal ...
- 63
0
votes
1
answer
37
views
Torque about an accelerating point
The total force acting on the pulley is zero so:
$$F = mg + T_1 + T_2 \tag{A1}$$
Analyzing the torque and angular acceleration about the actual axis of rotation, the axle
of the pulley, gives:
$$τ_{...
- 1
0
votes
1
answer
29
views
When a plane is accelerating upwards, why is both the upwards acceleration and gravitational acceleration positive?
At a weight m, a plane is acceleration upwards at rate of a. We also remember the value of g.
From my understanding, we have two opposite forces that we care about.
The force due the gravitational ...
- 7
-1
votes
1
answer
43
views
Car crash - distance and acceleration no friction or rotation [closed]
A small model car is released by my hand and goes down a ramp and hits a wall.
There is no friction or air resistance and the car is influenced by -9.8m/s^2 gravity.
Why does the maximum acceleration (...
0
votes
1
answer
47
views
How to calculate tangential and normal acceleration?
In a problem, I have the expression of acceleration and velocity in Cartesian coordinates , and it ask me to calculate the tangential and normal acceleration, so we don't know how I can do that, can ...
- 11
3
votes
1
answer
140
views
Why acceleration bigger when upward force is present?
Imagine object is falling down and has a mass of 1kg. There's an upward force on it of 50N. Let's calculate what the acceleration is.
$$ F_n = ma = 50 - mg = 50 - 9.8 = 40.2 $$
where ...
- 357
1
vote
2
answers
38
views
Acceleration of an object after overcoming static friction
Let us imagine a rough horizontal surface with static frictional coefficient $u$ and an object of mass $m$ sitting on that surface. The maximum static frictional force that can be applied is $uN$ ...
- 1,125
0
votes
2
answers
28
views
Average acceleration to distance travelled. Equation gives wrong answer
i wanted to verify the measured data with calculations. So i got two totally different answers when calculating average acceleration.
V0 = 0 km/h
Vf = 30 km/h = 8.33 m/s
t = 9.32 s
S = 55.59 m
So &...
- 3
1
vote
0
answers
93
views
What is the link between normal acceleration and radius of curvature? [closed]
hope you are well,
So , in my physics class we use graphical method to determine the radius of curvature and as we know this method isn't very accurate, so when I watch a YouTube video I find this ...
- 11
8
votes
3
answers
2k
views
Can a rotating object accelerate by changing shape?
Suppose an object is already rotating in a situation of no external forces such as gravity or friction. Is it possible or impossible for it's velocity (linear) to change by the shape of the object ...
- 109
1
vote
0
answers
75
views
Time dilation under constant acceleration
If I am given:
the distance of two points
the (constant) force being enacted on the object moving between those two points
how can I figure out:
the time it would take the object to reach the other ...
- 11
0
votes
1
answer
49
views
If centripetal acceleration is pointed radially inward and it has a value $Ac = v^2/r$ is there not a value for centripetal velocity?
In uniform circular motion, an object is said to move tangentially along a circular path with a changing tangential velocity but a constant tangential speed. The velocity changes because the direction ...
- 41
0
votes
1
answer
27
views
Finding the velocity when the force is in terms of position [closed]
(The unit of position, mass, time is m, kg, s.)
On a horizontal line, a force $F=-6x$ (where $x$ is in meters) is applied to a particle of mass $M=3$. When $x=3$, the velocity $v=6$. What is the ...
- 117
0
votes
0
answers
27
views
How would we perceive a pulse of light if we accelerated constantly in the same direction? [duplicate]
I'm watching this video (the link starts at the relevant timestamp) and am confused about one thing. Let's say I'm going at a constant speed of $0.99c$ in $+x$ direction (w.r.t Earth), and a pulse of ...
- 1,132
0
votes
1
answer
43
views
Coriolis Force question
Let's say a ball moves in an azimuthal path around a rotating disk. The Coriolis force on the ball is given by $-2m \omega \times v$. My intuition tells me that there would be no Coriolis force ...
- 21
2
votes
2
answers
71
views
Trying to gain better intuition about fictitious forces
Recently started doing some reading into fictitious forces. It's easy enough to understand when dealing with linearly accelerating frames but I find it more challenging to understand rotating frames ...
- 21
0
votes
1
answer
97
views
As the speed time graph for a body thrown vertically upwards is not differentiable at the top point so why acc. is taken as 9.8 m/s² at the top point?
In the shown speed - time graph for a body thrown vertically up there is a sharp kink in the graph at the instant for which body is at highest position ie not differentiable so we can't find ...
- 1,055
1
vote
1
answer
48
views
Earth surface acceleration and inertial geodesics
I hope this is an appropriate question for this forum. It is one I have struggled with for a while.
I read that in GR gravity is not a force, and that the apparent force we feel and can measure (eg ...
- 11
0
votes
2
answers
71
views
Why can't we feel Earth's acceleration? [duplicate]
The centripetal force on Earth is constantly exposing Earth to the acceleration. Why can't we feel this change of direction?
- 1
0
votes
2
answers
75
views
Does Newtonian mechanics define an absolute rotational reference?
I note that there are several question related to absolute rotation so this may be a duplicate but I didn’t see an exact double. In any case, mine is this:
In a hypothetical universe made up by only ...
- 333
0
votes
0
answers
26
views
Cyclist coasting on a plane road (only air resistance and rolling resistance apply)
I am currently trying to simulate a cyclist. Right now I am looking at the change of velocity when the cyclist is coasting on a plane road. These are the values I am using:
...
- 101
0
votes
1
answer
63
views
Change in $g$ effective due to rotation
$g$ effective at any latitude changes due to rotation of earth. Does it also change due to rotation when the body is at height or at depth or does it change only at the surface?
Edit: I am referring ...
- 39
0
votes
1
answer
44
views
Force exerted on vehicle when hitting an object [closed]
How can i calculate force that is exerted on a vehicle when it hits an object?
Vehicle speed is 40 km/h, mass is 1500kg
Object is standing still (speed is 0 km/h), object mass is 11kg.
Now this ...
- 3
4
votes
3
answers
2k
views
Does acceleration make you heavier?
I'm looking at this article from Scientific American: https://www.scientificamerican.com/article/star-wars-science-light-speed/#:~:text=Normal%20humans%20can%20withstand%20no,heavier%20blood%20to%...
- 81
1
vote
4
answers
67
views
How can I factor friction into acceleration, given power?
I'm trying to work out an acceleration curve for a vehicle for a simulation, but despite a bunch of research there are a couple of things I still don't understand.
First we have $P = mav$. Assuming ...
- 147
1
vote
1
answer
44
views
Confusion regarding net acceleration of the bob in the bottommost point of the trajectory of a pendulum?
Here is my analysis from the inertial frame on it:
At the bottom most point,
$g$ acting downwards
$v^2/r$ (centripetal acceleration) acting upwards
So the net acceleration, a = $(v^2/r)-g$ right?
...
0
votes
1
answer
22
views
Are terms tangential acceleration and normal acceleration only used for instantaneous velocity?
Are terms tangential acceleration and normal acceleration only used
for instantaneous velocity?
0
votes
1
answer
54
views
Proper acceleration along perpendicular directions
Let's take an object (all times mentioned in this problem are proper times). There is a constant proper acceleration
"$a$" on this object in the x-direction for time $t, 0\leq t \leq \tau$. ...
0
votes
2
answers
75
views
Does a simple pendulum have some radial acceleration at its extreme positions where its speed becomes zero?
Suppose we have a simple pendulum swinging between two extreme positions. At the extreme position its speed becomes zero. As per this reason can I say that at extreme positions radial acceleration (v^...
- 1,055
0
votes
1
answer
100
views
Why does a centrifuge cause blood to be pushed downwards in the human body?
Good evening all,
I recently watched this YouTube video about a centrifuge by Tom Scott
(https://www.youtube.com/watch?v=DMKcO-T5Y4o). Around the 2:30 mark, it is said that blood will be 'pushed ...
- 81
0
votes
1
answer
89
views
A way of expressing acceleration in general relativity
Using this question:
How can we recover the Newtonian gravitational potential from the metric of general relativity?
I want to formulate my question:
Can the first term of the energy-stress tensor, ...
- 97
0
votes
0
answers
49
views
About jounce (snap)
About jounce (snap). So change in acceleration is know as jerk, so like this is still imaginable but what is change in jerk, like can you give some real life example where that is happening.
