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.
A race car strarts from rest and travels east along a straight and level track.
For the firs $5.0s$ of the cars motion,
the eastward compent of the car's velocity,is given by
$v_x(t)=(0.930 m/s^3)t^2 $
What is acceleration of the car when $v_x=14.5$
ok my first step with this was...
Hi.
The energy required to accelerate an object of mass ##m## to a speed ##v## is ##E_k=\frac{m}{2} v^2##. But how much energy does an object need to accelerate itself to ##v##? Say, how much fuel (in energy units) does a car need to accelerate to ##v##, if there are no air resistance or...
The two spaceships A and B approach each other at constant speed v:
A----------B
There is no way of knowing if B is standing still while A is moving at speed v (to the right), or if A is standing still while B is moving at speed -v (to the left).
This shows that speed is relative.
But if the...
What is the acceleration of a body (you can consider it as a particle) moving in a circular path placed in the vertical plane as it passes through the bottom of the path? (Provided that the body is under its weight and the path normal only).
Homework Statement
A wheel of radius r1=0.8m and hub of radius r2=0.4m is shown in the diagram. Two masses are hung from the wheel-hub system. The mass m2, on the left, is hung from the hub. The mass m1 is hung from the wheel. The system is in equilibrium. The moment of inertia for the disk-hub...
Homework Statement
Referring to the attached diagram, the object ABCD is kept in an isolated system where it is under no external influence of any kind.
A· An instantaneous force F acts along the edge BC of the block ABCD, where M is its mass, with its center of mass located at O...
Imagine a long brick in outer space. You apply a force tangential to the center of mass. The brick accelerates in a transitional and angular fashion. There are no constraints or fixed axis. How would I calculate the translational and angular acceleration? I would like to run some simulations...
Currently design of turbomachinery (impellers/turbines) is more a form of art than an engineering process. One has to guess a bunch of parameters and check if they are right in much later stages of design.
I was thinking about designing the other way: we know the initial and the final velocity...
Let's say you have two rings. Both rings have the same radius and are aligned so that the holes are perfectly parallel to each other and a straight line can be drawn through them without interference. Both rings spin along the same axis with the same speed, but in opposite directions.
If you...
Imagine, There's a ball in deep space traveling with a constant velocity of 25m/s and is having mass 25kg.
Now as I said, ball is traveling with a constant velocity that simply means acceleration=0 and now if we calculate the force with F=ma we will end up with 0. But if that ball collide with a...
An antelope moving with constant acceleration covers the
distance between two points $\textbf{70.0m}$ apart in $\textbf{7.00s}$
Its speed as it passes the second point is $\textbf{15.00 m/s}$.
What is its speed at the first point?
The answer to this is 5 m/s
ok this should be real simple but...
Okay, so I am designing a new treadle hammer and I want to know how much force a spring will add to the force of the hammer.
Basically I have an 8 pound head that can either fall at the speed of gravity or be forced down by a 20lb extension spring.
The attached image is not my design and I...
Homework Statement
This problem showed up in my final review packet, and I /think/ it should be basic kinematics, but I don't even know how to approach it with the second half of it.
An object moves according to the equation x = vt + ke^(bt), where k, v, and b are constants, x represents...
Hi,
It's my first post here on the forum and I'm just looking for an answer to a basic kinematic movement equation.
This is the text of a problem:
"A bike accelerates uniformly from rest to a speed of 7.10 m/s over a distance of 35.4 m. Determine the acceleration of the bike."
Now, in the...
Homework Statement
a grinding wheel 0.5 m in diameter roates at a rate of 8.00 x 10^2 revolutions per minute. find the magnitude of the acceleration of a speck of metal cuaght in the outer edge of the wheel
Homework Equations
a=4pi^2r/T^2
[/B]The Attempt at a Solution
I was wondering if i...
Homework Statement
Suppose the acceleration of a particle is a function of x, where a(x)=(2.0 s-2)*x.
(a) If the velocity is zero when x= 1.0 m, what is the speed when x=3.0 m?
(b) How long does it take the particle to travel from x=1.0 m to x=3.0 m. a(x)=(2.0 s-2) * x
(a) V(x=3) = ? , V(x=1)...
An object, moving in a straight line, has a velocity of 5.0 m/s at time t = 0. From t = 0 to t = 5 s its acceleration is 2.5 m/s2 , while from t = 5 to t = 11 s its acceleration is - 0.1 m/s2 . Over the time interval t = 5 s to t = 11 s its average velocity is: (a) 15.0 m/s (b) 12.5 m/s (c) 17.2...
Homework Statement
A rocket blast off. In 10.0 seconds it is at 10,000 ft, traveling at 3600mph, The rocket is going straight up
Homework EquationsThe Attempt at a Solution
Homework Statement
A car at the Indianapolis 500 accelerates uniformly from the pit area, going from rest to 320km/h in a semicircular arc with a radius of 200 m. Determine the tangential and radial acceleration of the car when it is halfway through the arc, assuming constant tangential...
If me and my pet duck, who weighs next to nothing, were placed far away from any gravity source and in such a way that our mutual attraction was negligible, would I see my duck accelerate away from me? If so, how fast?
Homework Statement
A computer disk starts from rest, then speeds up with angular acceleration of 190 rad/s^2. until it reaches its final speed of 7200 rpm. How many revolutions will it have made 10.0 secs after starting up?
Homework Equations
w = w0 + at
rps = rpm / 60
1 rev = 2*pi rad
1 rad =...
Homework Statement
Homework Equations
d = vit + 1/2at^2
The Attempt at a Solution
Hey, so what i did was different from the answer key above. Instead of (4/5)^2 i did 1/ (4/5^2) so i got 25/16 as the answer. I'm not sure why tb/ta = 4/5 since 4/5 the time is referring to runner b's time...
Homework Statement
On a horizontal frictionless floor, a worker of weight 0.900 kN pushes horizontally with a force of 0.200 kN on a box weighing 1.80 kN. As a result of this push, which statement could be true?
A ) The box will not move because the push is less than its weight.
B ) The worker...
Hi, everyone. I'm working on a personal project and I need some insight from the intelligent minds here. I'm trying to calculate the thrust that a jet motor on a marine craft needs to exert in order to accelerate the craft in a certain direction. What are the necessary factors to determine the...
A non ionized neutral gas should still emit thermal radiation.,say xenon. Is this solely because of electron transitions ? I ask this because a lot of sources attribute the emission to charge particle acceleration,so neutral atoms should not do this,is this right?
In circular motion
1) V = rw and ##\vec V## = r ω##\vec e_{tan}##
2) a = rα and ##\vec a## = -##\frac{v^2}{r}####\vec e_{rad}## + rα##\vec e_{tan}##
Where ##\vec e_{tan}## is the unit vector along the tangent in increasing direction of θ
And ##\vec e_{rad}## is the unit vector along the radial...
Homework Statement
A ball with moment of intertia bmr^2 rolls without slipping down a plane inclined at angle O. What is it’s linear acceleration?
Homework Equations
Fnet= ma
T = F x r
T = IO’’
a = rO’’
The Attempt at a Solution
Fnet = mgcos(O) - FfT = FfrT = IO’’
Ffr = bmr^2O’’
Ff =...
Homework Statement
a block B of negligible mass is connected to a particle of mass 1 kg with a non-stretchable string. Now the hanging particle is given a velocity root(8gH) horizontally when system is at rest. Find the initial acceleration of block B.
Homework Equations
3. The Attempt at a...
This may sound like a noob question but please help me out guys.Will universal acceleration ever retard ? And if it continues to accelerate for all eternity, where is it getting this never ending energy from ?
How do you workout average acceleration without time?
I have Initial velocity ,final velocity & distance.
With this I have to workout...
1) Average acceleration
2) Time take to accelerate from initial to final velocity
Regards
Someone a little confused
Homework Statement
Ball A is dropped from the top of a building of height h at the same instant that ball B is thrown vertically upward from the ground. At what height will the balls collide if the collision occurs when the balls are moving in the same direction and the speed of A is 4 times...
Homework Statement
A jet pilot takes his aircraft in a vertical loop. V is 840 km/hr (233.3 m/s) find the min. radius of the loop to that the centripetal acceleration at the bottom does not exceed 6 Gs.
Homework Equations
a = v^2 / r
F = ma
The Attempt at a Solution
I don't know where to...
$\tiny{243.13.0113}$
$\textsf{The vector $r(t)$ is the position vector of a particle at time $t$.}]$
$\textsf{Find the angle between the velocity and the acceleration vectors at time $t=0$}\\$
\begin{align*} \displaystyle...
Homework Statement
An electron acquires 3.16*10^-16 J of kinetic energy when it is accelerated by an electric field from plate A to plate B. What is the potential difference between the plates, and which plate is at the higher potential.
Homework Equations
w =Δv * q
The Attempt at a Solution...
Homework Statement
An 82 kg man inside a 40-kg dumb-waiter pulls down on the rope. At that moment the scale on which he is standing reads 209 N. Determine the elevator's acceleration.
Homework Equations
F=ma
The Attempt at a Solution
I know the acceleration is 0.152 m/s^2 upwards , I need...
I may have a fundamental misunderstanding of the concept, but I was wondering, how does the accelerating expansion of the universe calculate for the time dilation in light travel?
From my understanding, we know that the universe expansion is accelerating because the farthest galaxies that we...
Homework Statement
Homework Equations
The Attempt at a Solution
The normal acceleration of the particle at any instant is given by an = v2/r . v is the speed at any time and r is the radius of curvature . Minimum radius will occur when ratio v2/an is minimum .
I think this will occur when...
So, I have this scenario:
A neutron star with radius R = 13 km
Time for 1 rotation is 3,150807 ms, so frequency f about 317,379008 Herz
Mass 1,97 times the Sun's which is then 1,97*(1,9884*10^30) kg
Extra given information: the magnetic axis is aligned with its rotational axis (not that likely...
Homework Statement
The power driving the railroad engine is switched off. The engine stops, from its speed of 16m/s^-1, without braking in a distance of 1.1km. A student hypothesis that the horizontal resistive force is constant. Based on the hypothesis, calculate the mass of the railway...
So this is my first time posting on here and I hope I'm doing right!
1. Homework Statement
A 75-kg snowboarder has an initial velocity of 5.0 m/s at the top of a 28 ∘ incline. After sliding down the 110-mlong incline (on which the coefficient of kinetic friction is μk = 0.18), the snowboarder...
A 50 kg box rests on the floor. The coefficients of static and kinetic friction are 0.70 and 0.50, respectively.
a.) What is the minimum force required to start the box sliding from rest?
b.) After the box starts sliding, the person continues to maintain that force. What is the...
Homework Statement
You hold a small ice cube near the top edge of a hemispherical bowl of radius 100 mm. You release the cube from rest. What is the magnitude of its acceleration at the instant it reaches the bottom of the bowl? Ignore friction.
Homework Equations
ΣF = ma
Fg = mg
The Attempt...
A girl is climbing up a set of stairs and has her femur horizontal. Her thigh weighs 12 pounds, acting at a center of mass 15 cm from her hip joint. She places 50 pounds of weight on the lower portion of that leg, vertically through her knee. Her gluteus maximus is applying a force directed 30...
Imagine a moving rigid body B1 like a golf clubhead impacts with a stationary elastic body B2 like a golfball. Imagine that the initial velocity of the golfball at time T1 is zero, and the final velocity of the golf ball at time T2 is some value. Imagine that time T1 is when the clubhead first...
Homework Statement
I have derived the expression for the velocity of the satellite v= root of GM/r however I'm struggling to derive an expression for the centripetal acceleration of a satellite orbiting Earth.
Homework EquationsThe Attempt at a Solution
I'm not entirely sure which equations to...
Hi,
I teach a physics class to a group of homeschooled students. Many of them aren't yet at the level of algebra.
Last week we went over Newton's laws and did some experiments to show objects fall at the same rate regardless of mass. One student though, has asked me to explain why the mass...
I found a problem and I'm having one question, it goes like this:
A box of 5 kg is being dragged across the floor with a horizontal force of 40 N. If it starts at rest and it begins to accelerate at 3 m/s2 (constant acceleration), find:
A) The coefficient of kinetic friction
B) Supposing that...
Homework Statement
https://isaacphysics.org/questions/gcse_ch2_13_q10
https://www.physicsforums.com/attachments/213735
https://i.imgur.com/WnZkt83.jpg
The thrust generated by a rocket engine is equal to the mass of propellant burnt each second multiplied by the exhaust velocity of the gas...
Hey guys, I'm working on a product that rotates cups around a shaft, I am trying to calculate the torque required to do so. I have given it my best shot below, does this seem right to you?
The Main Shaft Motor will need to rotate holder one from the filling cups position to the pressing lids...
What is the difference between tangential and linear acceleration of a circular object (let's say a ball)? Also, how does the torque contribute to linear acceleration?