What is Constant acceleration: Definition and 340 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 think it's not possible.
In 3D for constant acceleration we have : ##\vec v = \vec v_0 + \vec a t##
It's a line in 3 dimension so velocity's magnitude(speed) is changing with time.
I appreciate any better idea.
Hi all,
Let V be an initial velocity, D any distance, and T a time duration. which algorithm allows to obtain a constant acceleration A that make the object to brake from V to a zero speed over D during T?
Thanks
I got to the quadratic equation of the motion where: 4gt^(2) - g(delta t)t - g(delta t) = 0 and tried to solve for t. In this case, we would take the positive discriminate since we are dealing with the passing of time.
t = ((sqrt(17) g(delta t)) + g (delta t)) / (8g)
However, this is the...
My guess is that I could compare it to the time interval of the free fall motion(stage2).
Would that be enough to let it make ‘sense’?
As we know that stage 1 has an acceleration of 16m/s^2 and free fall one of 9.81m/s^2. Then.. is it sufficient to reason that the time needed to complete stage...
Consider a far-away galaxy that is considered to be currently receding from Earth at 2x the speed of light. (With this 2x c recession velocity, we are speaking of the Vnow, the imputed relative velocity of the galaxy compared to Earth now, not the velocity of the galaxy relative to Earth at the...
I thought I'd start by writing the problem in a tensor formalism. I have identified with ##S## the Earth and ##S'## the rocket. Since the acceleration provided is in the rocket's frame of reference, I can write the following four-vector.
$$
a'^\mu=(0, a, 0, 0)
$$
Since we are interested in the...
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...
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...
I tried this but I don't know if it makes sense:
Average velocity from A to B = 22/2 = 11m/s
Average velocity from B to C = 104/4 = 26m/s
(26-11)/6 = 3.75m/s
Initially we are given the statement Vav = (x-x0)/t, so far so good. But, we encounter the following paragraph...
"We can also get a second expression for Vav that is valid only when the acceleration is constant, so that the v-t graph is a straight line (as in Fig 2-14 - [I've omitted the graph...
I've been attempting to solve this problem for three days now. I have thrown away my old attempts (like, scrumpled up into the bin), but my old attempts involved:
Trying to set up simultaeneous equations relating the journeys between EH and FG to find the deceleration, but the reason why this...
a = (change in magnitude of velocity) + (change in direction of velocity)
→ Can you feel when you change direction? Even if force and acceleration are constant?
↑ ↓
↑ ↓
↑ ↓
o
2.3.16 A car is traveling at $45 \, km/h$ at time $t=0$ It accelerates at a constant rate of $10 \, km/h\, s$
(a) How fast is the care going at $t=1\, s$?
$$v_t=v_0+at=45+10(1)=55\,\dfrac{km}{h}$$
at $t=2\,s$
$$v_t=v_0+at=45+10(2)=45+20=60\,\dfrac{km}{h}$$
(b) What is its speed at a...
I'm just having trouble understanding 1) how to plug in the formulas correctly and 2) the correct manner of attacking this.
I feel like I'm missing something basic/simple. Any help is greatly appreciated! So far I've got:
D = (0) + .5(2.2m/s^2 x 2.4s)^2
Enrique
Sample Problem 2.04 Drag race of car and motorcycle
I was following all the way up to using the quadratic equation for this problem...(please see img for a more detailed attempt at a solution.)
So I may have simplified incorrectly here:
but I came up with
2.8t^2-(58.8)t+408.1=0
but when...
Homework Statement
Serway Physics - P2.40
A glider of length 12.4 cm moves on an air track with constant acceleration (Fig P2.39).
A time interval of 0.628 s elapses between the moment when its front end passes a fixed
point A along the track and the moment when its back end passes this pont...
Homework Statement
I am solving a kinematic problem, where I have a link that is attached to a rotational joint. I need to find the position of the joint for t=0..8, and I need to do it for every 0.01s. The problem comes from the fact that I have three stages for the velocity, during t = 0..0.1...
Homework Statement
persons 1 & 2 are initially at rest (vi=0m/s) 48m (d) apart. they then run towards each other at constant accelerations
person 1 acceleration = 0.50m/s2
person 2 acceleration = 0.30m/s2
how long until they reach each other/collide (t)?
at the instant they collide, how far...
If I throw the electron from electron gun with some acceleration .Will it maintain it's constant acceleration? If yes then it radiates photons from where will the electron gets energy to constantly radiate photon? If not then why?
A constant tangential force of magnitude 12N is applied to the rim of a stationary, uniform circular flywheel of mass 100kg and radius 0.5m. Find the speed at which the flywheel is rotating after it has completed 25 revolutions?
I know that this can be done using work-energy. But since a...
I was in a discussion regarding the time it took to get to the speed of light with a constant acceleration of 1g, and the time was something close to a year. (ignoring all the other major factors ). Just from a Newtonian perspective, if you have a 100kg rocket putting out 900N of thrust, you...
Homework Statement
Train starts to travel in a straight line at increasing speeds. The first wagon passes next to me in 4 seconds. In how many seconds will the n-th wagon pass next to me?
Homework Equations
s= vo.t + 1/2at^2
v= vo + at
The Attempt at a Solution
First of all we didn't learn...
Homework Statement
a) A ball is thrown in the -y direction off of a cliff with a velocity of 7m/s. If the ball takes 1.45s to reach the ground, how high off of the ground is the cliff? (Answer: -20m)
Homework Equations
Vf=Vi+a(t)
Displacement=Vi(t)+1/2a(t)^2
Vf^2=Vi^2+2a(Displacement)...
Hi, I am trying to wrap my brain around special relativity equations but I'm struggling with the math. I am a computer programmer comfortable with the algebra and but never studied calculus or physics.
Say I am already traveling at velocity "v" where "v" is approaching the speed of light. I...
Suppose a comet F ,at 1 AU distance, is traveling toward a massive body (a neutron star or other) with v= .99 c, suppose also that a = 3 km/s^2 and (to simplify calcs) that it is uniform from there to the star. It will hit the star after ca. 1000 seconds and its speed should equal C: 297*10^9...
Homework Statement
African baobab trees can have circumferences of up to 43.0 m. Imagine riding a bicycle around a
tree this size. If, starting from rest, you travel a distance of 162 m around the tree with a constant
angular acceleration of 5.00 × 10–2 rad/s2, what will your final angular...
Homework Statement
A rocket is flying away from the Earth with a costant acceleration ##a## in a frame in which the rocket is at rest. Finding the equation of motion (the relation between the distance from the Earth and the terrestrial time). Showing that there is a maximum time ##T## after the...
Homework Statement
[/B]
An X-ray tube gives electrons constant acceleration over a distance of 14 cm . If their final speed is 1.0×107 m/s , what are the electrons' acceleration?
Express your answer to two significant figures and include the appropriate units.
Homework Equations
My prof. has...
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...
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
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...
Homework Statement
A car is moving with a constant velocity of 18 m/s for 5 seconds, if in the next 5 seconds it travels a distance of 40 m, what is its final velocity?
Homework Equations
Δx= vit+ 1/2 at^2
vf= vi+at
vf^2 = vi^2 + 2a (Δx)
The Attempt at a Solution
So I tried doing it different...
Homework Statement
A car, length 2.4m, traveling at 26m/s wants to pass a large truck, length 12m, also traveling at 26m/s. If the car can accelerate at 4.4m/s2, how much time will it take the car to pass the truck (note the back of the car has to be in front of the truck)? How far will the car...
Hello,
I just did a practice physics problem that asked if an object with constant acceleration can change direction twice. The answer was no. What if you had an object attached to a string spinning at constant velocity. Is the tangential acceleration constant?
Homework Statement
Hi, I have a quick question about an experiment I am doing.
I did an experiment where I rolled a ball over a flat surface and dropped a ball from a height, and I was asked if the ball rolling over the flat surface (1-d) motion is subject to constant velocity? I was also...
Homework Statement
A hot air balloon is released from the ground & rises up with a constant acceleration of 4 m/s^2. When it is 16 meters above a sandbag is dropped.
What is the time taken for the sandbag to hit the ground?
Homework Equations
v^2=u^2+2as
v=u+atThe Attempt at a Solution...
In the equation v=u+at, u=5 m/sec and a=0, then v=5 m/sec. That means the body is moving with a constant velocity of 5 m/sec. In a velocity-time graph, the equation produces a straight horizontal line. Some texts say the body is moving with zero acceleration and others say it is moving with...
according to f=GMm/r^2 if force changes based on a distance between 2 objects, so during free fall object is constantly changing its distance, so does that mean the Earth is exerting a non-constant force on that object? if that was right, why's that object accelerate at a constant rate of...
Homework Statement
A box is sliding with constant acceleration a to the right. Inside the box there is a quarter of a circle upon which a frictionless ring can slide. Find the angle theta in terms of the other given variables.
Picture in solution
Homework Equations
F=ma, etc. basic stuff...
Homework Statement
Large cockroaches can run as fast as 1.50 m/s in short bursts. Suppose you turn on the light in a cheap motel and see one scurrying directly away from you at a constant 1.50 m/s. If you start 0.91 m behind the cockroach with an initial speed of 0.82 m/s toward it, what...
Homework Statement
"The fastest measured pitched baseball left the pitcher's hand at the speed of 45 m/s. If the pitcher was in contact with the ball over a distance of 1.50m and produced constant acceleration, (a) what acceleration did he give the ball, and (b) how much time did it take him to...
Homework Statement
A man was driving a car at 78 km/h, he saw a deer at the distance of 101m, how much time is needed so that the car slows down after it drove 99m and stops.
Homework Equations
Δx = 1/2 (vi + vf) * t
The Attempt at a Solution
I'm thinking about finding the Δx
1. Homework Statement
3 blocks A,B and C are attached between them by massless and frictionless strings , that passes through frictionless , massless pullies , the blocks A and B have the same weight 25 N and the same coefficient of kinetic friction 0.35 , the bloc C goes down with a constant...
I am coding a game in which I desire a projectile to undergo realistic curving when rotating while moving through the air. Let's consider the instance of a projectile that is initially moving forward while spinning clockwise along an axis placed vertically in it is center of mass. The object...
Homework Statement
Homework Equations
F=m*a
ΣF=0
The Attempt at a Solution
Firstly, I tried to work on the normal force of bowling ball. But I can't get the answer. I don't get the idea that bowling ball could be kept at constant height, I didn't really understand the question guess. Can...
Homework Statement
A falling stone takes 0.28 s to travel past a window 2.2 m tall.
From what height above the top of the window did the stone fall?
So from this problem I think I have these variables:
vo = ? (or 0 because falling usually indicates 0 for an initial velocity?)
yo = 0
y = 2.2m...
Homework Statement
A 747 Jumbo Jet must reach a speed of 290km/h by the end of the runway to lift off. The 15L-33R runway at Toronto International Airport is 2,770 meters long. The main Toronto Island Airport runway 08-26 is 1216 meters long. Assuming the jet has a constant acceleration, for...