What is Acceleration: Definition and 1000 Discussions
In mechanics, acceleration is the rate of change of the velocity of an object with respect to time.
Accelerations are vector quantities (in that they have magnitude and direction). The orientation of an object's acceleration is given by the orientation of the net force acting on that object. The magnitude of an object's acceleration, as described by Newton's Second Law, is the combined effect of two causes:
the net balance of all external forces acting onto that object — magnitude is directly proportional to this net resulting force;
that object's mass, depending on the materials out of which it is made — magnitude is inversely proportional to the object's mass.The SI unit for acceleration is metre per second squared (m⋅s−2,
m
s
2
{\displaystyle {\tfrac {\operatorname {m} }{\operatorname {s} ^{2}}}}
).
For example, when a vehicle starts from a standstill (zero velocity, in an inertial frame of reference) and travels in a straight line at increasing speeds, it is accelerating in the direction of travel. If the vehicle turns, an acceleration occurs toward the new direction and changes its motion vector. The acceleration of the vehicle in its current direction of motion is called a linear (or tangential during circular motions) acceleration, the reaction to which the passengers on board experience as a force pushing them back into their seats. When changing direction, the effecting acceleration is called radial (or orthogonal during circular motions) acceleration, the reaction to which the passengers experience as a centrifugal force. If the speed of the vehicle decreases, this is an acceleration in the opposite direction and mathematically a negative, sometimes called deceleration, and passengers experience the reaction to deceleration as an inertial force pushing them forward. Such negative accelerations are often achieved by retrorocket burning in spacecraft. Both acceleration and deceleration are treated the same, they are both changes in velocity. Each of these accelerations (tangential, radial, deceleration) is felt by passengers until their relative (differential) velocity are neutralized in reference to the vehicle.
I'm trying to simulate the physics of a Toyota Camry during acceleration with a time granularity of 100ms. My simulated conditions are as follows:
m = 1590 kg
v = 17 m/s
a = 1.5 m/s2
η (transmission efficiency) = 0.85
rwheel = 0.35 m
Fdrag = 100 N
Ffriction = 260 N
Faccel = 1590 kg × 1.5 m/s2 =...
(a) Using COE,
$$mgh = 0.5mv^2 + 0.5I\omega^2$$
I solved it, where $$\omega = 112 rad/s$$
(b) This is the part where I have question or problem.
I saw my course mate working and he start of with finding centripetal acceleration.
$$a_c = \frac{v^2}{r} = \frac{(r_0\omega)^2}{R_0}$$
Why isn't it...
So the teacher said that acceleration was the rate of change for velocity
so in 3 minutes the velocity of the election needs to go to 200m/s
so i used the formula and I found that every minute the electron needs to accelerate at 66.7m/s2 to reach 200m/s in 3 minutes
and for each second it...
Like I said, objects with the higher acceleration are giving me the lowest values. For a hoop, I got I=0.1*MR^2
For a cylinder, I got I=0.7*MR^2
this seems backwards, no?
Okay so I actually have the answer because my teacher basically just gave it to me, but I would really like to know why I was even wrong in the first place. Here's my steps:
1. Knowing the momentum transfer per unit area is described by: 1/A dp/dt = S/c. I can begin by relating some known...
when electron is moving around it like it accelerate and so it create magnetic field. and when mass accelerate it create gravity radiation , we also know that the gravity is not actuall force and it just change the time so when the Earth move in 4 direction it change it path becuase time change...
Hi,
Riders in an amusement park ride shaped like a Viking ship hung from a large pivot are rotated back and forth like a rigid pendulum. Sometime near the middle of the ride, the ship is momentarily motionless at the top of its circular arc. The ship then swings down under the influence of...
Hi,
A mother pushes her child on a swing so that his speed is 9.00 m/s at the lowest point of his path. The swing is suspended 2.00 m above the child’s center of mass.
(a) What is the magnitude of the centripetal acceleration of the child at the low point?
(b) What is the magnitude of...
Okay so what I've done;
I've put the diammter d = 1m as r = 1m
The time interval of 4s is t = 4s
and the angular velocitys as;
ω1 = 20 rad/s
ω2 = 40 rad/s
Now to get the accelaration. Angular acceleration can be split into two parts tangetial acceleration and radial acceleration
What I...
Can special relativity handle acceleration? I believe the answer is yes, but I don’t recall dealing with any acceleration problems when I took SR. I remember using the time dilation, length contraction and Lorentz transformation equations. These equations all assume constant motion iirc.
Hi All,
Please see attached photo of the question.
It is asking for net force and acceleration. Taking the forces acting upwards and downwards on the
parachutist as vectors: for A the net force would be 800-300=500; B would be 0 and C; would that be 800-1500=-700? And if so would that imply...
I am a self learner. I have a specific question regarding the Coriolis inertial acceleration. If question is already answered on this forum please redirect me there.
As depicted on the picture we have rotating platform and the chain of particles passing across the rotating platform. The...
Assume the jet is straight but the radius of the jet varies over it's length (like a jet of water falling which narrows due to gravitational acceleration). Also ignore viscosity. A pressure gradient would be required to accelerate the fluid radially. Because during an expansion transformation...
m1 = top left
m2 = bottom left
m3 = top right
m4 = bottom right
My questions:
1. Will all the object (m1, m2, m3,and m4) have same acceleration?
2. Should I assume initial extension of both spring is the same? (only based on the picture)
3. Will the extension of the spring change after the...
Hello!
I am trying to solve for the velocity in terms of position of a particle moving with non-constant acceleration.
a=c*t (where c is a constant)
I can easily solve for velocity in terms of t.
dv/dt=a
dv/dt=c*t
I differentiate and get v=1/2*c*t^2+v0 (where v(0)=v0)
However I am not sure...
I did (0.9-0.1)/(1.5-0.5) = 0.8/1 --> 0.8 m/s^2
This doesn't look right to me. Is this actually correct or do I need to solve the problem a different way?
Multipart question:
1) How long would it take to travel to the moon from Earth at a constant 1 g acceleration?
2) How does fuel consumption work with constant 1 g acceleration or acceleration in general? I read that "it doesn't take a constant amount of energy to maintain a constant...
The displacement of the particle is;
s= ∫v dt
s= ∫4-3t^2 dt
s=4t-t^3+c
When the particle is at the Origin, t=0;
0=4(0)-(0)^3+c
c=0
So this becomes;
s=4t-t^3
The particle next passes through the origin when;
4t-t^3=0
Factor out the common term -t;
-t(t^2-4)=0
Rewrite t^2-4 as t^2-2^2 and factor...
An elevator in outer space where there is negligible gravity, accelerates at the most precise constant acceleration that current technology enables.
Inside that elevator, resides an accelerometer that is the most precise accelerometer that current technology enables, but not more precise than...
Hi. I am looking for some references of acceleration frame in SR, such as an accelerating rocket problem.
I have some equations regarding the time, distance, velocity measured in the Earth frame, etc. But the reference I have does not provide the derivation of those equations, so I need some...
Normal acceleration is equivalent to a uniform gravitational field throughout all of space. Thus, if I am normally accelerating, I should observe an event horizon shifted as compared to a non-accelerating observer. Is this correct?
Let ##μ_k## = 0.5
##F_a## = 10 Newtons
##\theta## is the angel of the Applied force.
How will the acceleration of the block change if the angle of the applied force is increase by ##5^o##? Write Increase, Decrease or Stay the same.
Recently we were discussing a question similar to this in...
Given such a diagram as shown above, we know that the normal force must be mg/sintheta. How is this normal force greater than the gravitational force conceptually? Is it due to the horizontal traveling (which must have been started by someone exerting a force?) compressing the sides of the cone...
(1) Uniformly moving frames
I begin with a drawing of the situation. The events are labelled as ##\color{red}{E_1}## and ##\color{red}{E_2}##. We note the time of those events : ##t_1 = t'_1 = 30s## and ##t_2 = t_2' = 30+60 = 90s##.
I attempt the problem in two different ways.
(a) By...
I have some troubles with this relatively simple problem My idea was to find the acceleration by F = ma and then integrate the graph and then find the velocity to t = 10 s + start velocity
The graph will be
- 2x
And integrated
-x¨^2
But this seems wrong
Thanks in regards
Say that we have an instance where something falls down from a certain height with constant acceleration g. We know that the average speed with regards to the time period is less than (u+v)/2 since we spend less time at the higher speeds.
How do we actually calculate the average speed over a...
I am not sure about my free body diagram. I assume the cylinder rolls without slipping so the forces acting on the cylinder are:
Weight directed vertically downwards
Normal force directed perpendicular to the plane
friction directed upwards, parallel to the plane
Am I correct till this point...
First and foremost, thank you so much for your help! I'm new to Physics Forums, and this is my first post.
I thought I understood the problem, but as I moved on to the subsequent parts of it became apparent that I was missing something. I set up my ##F = ma## equation as below, and solved that...
a) ##a_y=\dfrac{\sum{F_y}}{m}=\dfrac{N-mg\cos{\alpha}}{m}=(1-\cos{\alpha})g##
##a_x=\dfrac{\sum{F_x}}{m}=\dfrac{mg\sin{\alpha}}{m}=g\sin{\alpha}##
##a_y=(1-0,866)9,81\;m/s^2=1,31\;m/s^2##
##a_x=(0,5)9,81\;m/s^2=4,91\;m/s^2##
How can it be a perpendicular acceleration?; which coordinate system am...
Bob is standing on Earth and Alice is on a distant planet at a constant distance from Earth. Their watches are already synchronized in the following sense: Suppose Alice's planet is a light-year away from Earth. Bob emits a light signal to Alice at time t = 0 according to Bob's watch. When Alice...
I was watching the above video which is part of a series explaining the mechanics behind a gyroscope. In the video the author explains the mechanics of the gyroscope when stationary (the disc is not rotating). Here he derives a result that the angular acceleration is g/r which is non zero...
In the example above, the authors claim that when ##r=r_0e^{\beta t}##, the radial acceleration of the particle is 0. I don't quite understand it because they did not assume ##\beta=\pm \omega##.
Can anyone please explain it to me? Many thanks.
Basically I just want to work out a constant acceleration problem in relativity, of the same kind of introductory physics.
Vo= 0.9999c
Vf = 0
D= 50 Au
Accel, Earth frame?
Accel, Ship frame?
Time of transit, Earth frame?
Time of transit, ship frame?
Motion is 1-D. All origins line up at the...
##\vec r=r \hat r##
##\vec v=\dot r \hat r + r \dot \theta \hat \theta##
##\vec a = (\ddot r - r \dot \theta^2)\hat r + (2 \dot r \dot \theta + r \ddot \theta)\hat \theta##
Given that,
##2 \dot r \dot \theta + r \ddot \theta =0##
Also,
##r \theta=constant##
##\Rightarrow \dot r \theta + r \dot...
In order to find force( and hence the Acceleration) on the Pentagonal plate,we must find the Resistance of the plate.But to find the resistance we must know how the current is flowing through the given plate(see attached figure).
My question is how is the current flowing through the Pentagonal...
vavg=(Vi+Vf)/2
vavg=h/t
then vavg*t=h
h=(Vi+Vf)/2 * t
Vf=at
(Vit+at2)*1/2=h
But formula on every resource I found says it should be;
(Vit+at2*1/2)=h
What mistake did I do ?
I initially attempted to get the answer by multiplying the mass by 50, as I assumed if the upward acceleration was 5g then the weight could be found by just multiplying the mass by the acceleration of 50ms^-2. However that resulted in an answer of 3750 which was far below the correct answer of...
Say... A ball is moving to the right, and we want to say that it doesn't slip.
My doubt is, in which case we put
Vrot = - Vcm = - α*r
or
Vrot = Vcm = α * r
I´m currently studying Newtons 2nd law and I don't get how can force only depend on mass and acceleration and not on velocity..
I mean, if I punch something with my fist going at constant velocity ( acceleration=0) it stills has a force right?
I know the acceleration of the rock is equal to g, but why. If we neglect air resistance, what is actually making the rock fall? Wouldn't it be that g overcomes the acceleration of the y plane at some point so the rock starts coming down or in this case accelerate more by throwing below 0 degrees?
Okay, here is a question I just can't solve.
The 120W motor starts to lift a load of 20 kg. During which time, this load will reach a speed of 0.5 m / s, taking into account the potential energy.
PS: Ignore losses in the mechanism!
1. When calculating a car's acceleration, is it ok to substitute Torque into a= F/ma= F/m
T= FrF= T/rwhere
a= acceleration,
F= force,
m= mass,
T= Torque,
r= radius,a= T/rm ?
[Mentor Note -- OP deleted his posts after receiving help. His posts are restored below]
@ocean1234 -- Check your messages. Deleting your post is not allowed here, and is considered cheating.
Problem was given: ##\theta(t) = at - bt^2 + ct^4##
a) calculate ##\omega(t)##
b) calculate...
I first calculated initial velocity:
√7.09^2+1.07^2=7.17028
acceleration=√7.22^2+2.47^2= 7.63
then i substituted all values into this equation:
final velocity=initial velocity + acceleration x time
so, final velocity=82.0285
so the magnitude=
final velocity-initial velocity= 74.858271
is...
Hi,
I am building a drone for a school project and I am also looking into how it flies. Recently I have been looking into angular momentum, torque, moment of inertia and angular acceleration. However I am struggling to understand moment of inertia and angular acceleration. If possible please...
Hey guys,
Theres something I've been confused about when looking at circular motion. When does an object have just centripetal acceleration as the acceleration of the object, if ever. I think that the acceleration vector is between the centripetal and tangential acceleration when an objects...