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.
Homework Statement
If a midpoint of a guitar string executes simple harmonic motion following the form x(t)=Asin(wt+φ), and its angular frequency is ω = 2.76 × 103 s−1 and A=1.60mm. What is then its maximum speed of the string during this motion? And what is the maximum magnitude of the...
As we know, POWER is what accelerate a car, FORCE itself doesn't accelerate a car, if FORCE cousing movement it change into work, and work over time = POWER.
The FORCE from jet engine pushes a plane forward. But as we know (or I'am wrong) FORCE don't push enything, only POWER couses...
Object with mass ##m## is sliding down a sloped (incline = ##\alpha##) object of mass ##M##. The coefficient of kinetic friction acting between ##m## and ##M## is ##\mu##. There is no friction between object ##M## and the ground.
In the drawing above, the red vectors above are the forces acting...
Homework Statement
Serway Physics Section 2.4 Acceleration
(a) Use the data in Problem 5 to construct a smooth graph of position
versus time. (b) By constructing tangents to the x(t) curve, find the instantaneous
velocity of the car at several instants. (c) Plot the instantaneous velocity...
Homework Statement
Serway Physics Section 2.4 Acceleration
17. Figure P2.17 shows a graph of ##v_x## versus t for the motion of a
motorcyclist as he starts from rest and moves along the road in a straight
line. (a) Find the average acceleration for the time interval t = 0 to t = 6.00 s.
(b)...
Is there some rule or standard that determines whether we define a vector with upper or lower case? I have not been told of any particular rule but it seems with velocity and acceleration they are lower case but force has always been upper case from what I've been reading so far.
Is there a...
Homework Statement
A rocket, total mass 1.00 × 10^4 kg, is launched vertically; eighty per cent of the mass being fuel. At ignition, time t = 0, the thrust equals the weight of the rocket. The ejected exhaust gases have a speed of 9.00 × 10^2 ms ^–1. Assuming the rate of fuel consumption and...
Homework Statement
Serway Physics Section 2.4 Accerleration
16. A child rolls a marble on a bent track that is 100 cm long as shown in Figure P2.16.
We use x to represent the position of the marble along the track. On the horizontal sections
from x=0 to x=20 cm and from x=40 cm to x=60 cm, the...
Homework Statement
Serway Physics Section 2.4 Acceleration
15. A velocity-time graph for an object moving along the x-axis is shown in Figure P2.15.
(a) Plot a graph of the acceleration versus time. Determine the average acceleration of
the object (b) in the time interval t=5.00 s to t=15.0 s...
Homework Statement
Serway Physics Section 2.4 Acceleration
14. A 50.0-g Super Ball traveling at 25.0 m/s bounces off a brick wall and rebounds
at 22.0 m/s. A high-speed camera records this event. If the ball is in contact with the
wall for 3.50 ms, what is the magnitude of the average...
Homework Statement
Objects X and Y, shown below, are released fronm rest in outer space. The only force acting on the objects is their mutual gravitational attraction. The mass of X is one-half that of Y. With respect to the original rest frame, the magnitude of the acceleration of X is
(A)...
Hello there, i have a confusion about the force concept itself because when i look dimensionaly i see that N = kg.m/s^2 but i do not understand how the force interacts with time. Is it just about where the object and what is the net force on it due to a reference frame at that moment ? Or...
Homework Statement
(Translating from a Polish high school textbook, so if anything is unclear please let me know).
An object moves on a trajectory described by the parabola ##y=\frac{1}{2\lambda}x^2## such that the ##x## component of its velocity is constant and equal to ##v_0##. The...
Homework Statement
In the figure below, a constant horizontal force app of magnitude 18 N is applied to a uniform solid cylinder by fishing line wrapped around the cylinder. The mass of the cylinder is 19 kg, its radius is 0.11 m, and the cylinder rolls smoothly on the horizontal surface.
(a)...
Homework Statement
Find the magnitude in g's of the Coriolis acceleration due to the Earth's rotation of a plane flying 600 mph due north over the location of latitude (37˚13'04"N), longitude (121˚50'39"W), at an elevation of 80 meters above mean sea level.
Homework Equations
aCor = 2Ω × vxy...
Homework Statement
Acceleration is defined as the second derivative of position with respect to time: a = d2x/dt2. Integrate this equation with respect to time to show that position can be expressed as x(t) = 0.5at2+v0t+x0, where v0 and x0 are the initial position and velocity (i.e., the...
Homework Statement
"A compact disc (CD) stores music in a coded pattern of tiny pits 10−7m deep. The pits are arranged in a track that spirals outward toward the rim of the disc; the inner and outer radii of this spiral are 25.0 mm and 58.0 mm, respectively. As the disc spins inside a CD...
Homework Statement :
[/B]
Homework Equations : F = ma[/B]The Attempt at a Solution :
[/B]
The sum of the vertical forces for the second block is (mg) - T (tension). The tension of the second block is the parallel component of the first block which is (mgsin40). Therefore, the sum of the...
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
A person stands on a bathroom scale in a motionless elevator. When the elevator begins to move, the scale briefly reads 1.05 times the persons regular weight. Calculate the magnitude and direction of the acceleration of the elevator.
Homework Equations
F=ma
The Attempt at a...
Homework Statement
We had a lab on projectile motion and one of the questions was this:
Use your Vy versus t graph to determine the y-component of the acceleration of the puck. Should this be equal to the acceleration due to gravity (9.8 m/s)? Explain why it is or why it is not.
The...
Hello,
I haven't been able to find the answer to this anywhere.
When calculating the energy gained by a particle that is accelerated across the gap of two cavities (e.g. Dees in a cyclotron, or charged cylindrical cavities of a linear accelerator), does one need to take into account the size of...
Homework Statement
An object moves at constant speed in a circular path. True statements about the motion include which of the following?
a) the velocity is constant
b) the acceleration is constant
c) the net force on the obj is 0 since its speed is constant
Homework Equations
hm none...
Hello there, i have a question that confuses me a lot. Is there a difference between the way that we think about time in many classical physics concepts as if it goes to a negative number. For example, we have dv/dt and we can be sure if velocity increases with respect to time and respect to our...
Homework Statement
Assume that the block on the table (Figure 1) has twice the inertia of the hanging block.
(a)You give the block on the table a push to the right so that it starts to move. If the magnitude of the frictional force exerted by the table on the block is half the magnitude of...
Homework Statement :
[/B]
It may be impossible to solve without the picture. Therefore, I linked the picture instead of typing the question.
Link/picture of question: https://gyazo.com/124652a4718764aa0f7e8217c1d3fcbc
I'm stuck on the third question.
The third question is the following: "What...
When I think about it, I see galaxies getting farther away with a constant acceleration. An acceleration that must be caused by a force ( pinned Dark Energy ). I lack in knowledge of the subject but yet I wonder what is the value of the acceleration in the expansion of the universe. Just like in...
Homework Statement
Two-thirds of the weight of a 2000 kg car rests on the drive wheels. What is the maximum acceleration of this car on a concrete surface?
Homework EquationsThe Attempt at a Solution
Shouldnt I have been provided mu, the coeeficient for friction? Its a mastering physics...
Homework Statement
3. (a) If an object's acceleration is zero in one inertial reference frame then is its acceleration zero in all other inertial reference frames? (b) If an object's velocity is zero in one inertial reference frame then is its velocity zero in all other inertial reference...
Hi,
If I find out the tangential force on the bob at position 1, it turns out to be m*g*sinθ. From this if I find out acceleration by dividing this equation by m, I get only g*sinθ.
Does it mean the max acceleration of pendulum has got nothing to do with its length or mass but theta?
1. Derive an equation for the acceleration of both the cart and suspended mass in
terms of both masses (Mc and Ms ), the angle of the incline (θ), and the acceleration due to gravity (g).
Homework Equations
Fx=
T - Mgsin θ = Ma
T = Mgsin θ + Ma
Fy
T = mg - ma
Combine the expressions...
In electron cyclotron resonance of metals/solids can there be electron acceleration without them engaging in collision ? I read the last para of electron cyclotron resonance wikipedia page which stated this
My question is why isn't the radial component e→r of acceleration in cylindrical coords simply r'' ?
If r'' is the rate at which the rate of change of position is changing in the radial direction, wouldn't that make it the radial acceleration? I.e, the acceleration of the radius is the...
In feynman lectures on physics volume 1
Excerpt 11-6
I don't get how the equation \begin{equation*} \Delta v_\perp=v\,\Delta\theta \end{equation*} is found.
Homework Statement
Two blocks of the masses m1=7.40 kg and m2=m1/2 are connected via a massless pulley and massless string. The system is currently in equilibrium but is about to start sliding, if m2 would increase even by a bit. For the friction between the surface and m1 assume that µs=µk...
Homework Statement
acceleration of certain oscillating particle described by a = -x/9 determine the position of this particle when t = 3π/2
if when t=0 x=0 and v=v0
Homework Equations
dv/dt=a
The Attempt at a Solution
frankly I am not sure how to start but i have two ways in my mind(even i...
Homework Statement
A 50.0 kg rocket is launched straight up (we’ll call this the y direction). Its motor produces constant acceleration for 10.5 seconds and stops. At the time of 12.5 seconds the altitude of this rocket is 333 m. (ignore air resistance and take g=9.80m/s^2)
a. What is the...
Homework Statement
A rifle bullet of mass 10g is fired and takes 2.0 ms to travel down the rifle barrel of length 0.50m with constant acceleration
Calculate the muzzle velocity (bullet velocity on leaving the barrel)
Calculate the acceleration in the barrel
After traveling a short distance...
Homework Statement
A centrifuge is a laboratory device used for spinning samples of material. In a blood centrifuge, a test tube is inserted at an angle θ=32.0° with respect to the vertical and the whole sample is spun at high speed. For a typical test that is l= 15.9 cm long and is spun in...
Homework Statement
A long block of ice is resting on a table. A long trough with parabolic cross-section is cut out of the ice with length between the focus and the vertex of a=7.76 cm. A small puck with mass m2 = 0.751 kg is placed a distance h=16.8 cm above the bottom of the trough. What...
Homework Statement
A a block of ice with mass mA rests on a wedge of ice with mass mB=4.33 kg that is cut so that the surface of the wedge makes an angle of θ=38.1° with the ground. There is no friction between the pieces of ice or between the ice and the ground. At time t=0, the blocks are...
Are two objects, accelerating at the same rate, and in the same direction, considered inertial to one another? If so, I will post my resulting question. If not, it's safe to disregard this thread.
Thanks,
Jake
Homework Statement
A block of mass 2.42kg is accelerated across a rough surface by a rope passing over a pulley, as shown in the figure below. The tension in the rope is 13.9N, and the pulley is 12.3cm above the top of the block. The coefficient of kinetic friction is 0.395. (a: 2.28m/s^2)...
Homework Statement
Hello PF!
Got a two-part question involving calculating the electric force on a electron when placed in an electric field of 0.75N/C to the right, and the acceleration of said electron. Our values are E=0.75N/C, q=-1.6e^-19, m=9.1e^-31 (charge and mass of electron)...
Homework Statement
A block of mass 2.42kg is accelerated across a rough surface by a rope passing over a pulley, as shown in the figure below. The tension in the rope is 13.9N, and the pulley is 12.3cm above the top of the block. The coefficient of kinetic friction is 0.395.
A: 2.28 m/s^2...
Homework Statement
Homework Equations
The Attempt at a Solution
I used Pythagorean theorem to find the length of the ramp (25^2+18^2 = √949) and found the angle of elevation using tangent (Tanθ=18/25) but then got stuck on what formula to use.
Problem:
https://drive.google.com/open?id=19PDuyshgP6u4U9mXU3BfrF031J8wL12B
Attempt: I tried to solve the range by listing out the Newton's 2nd laws of each drum
https://drive.google.com/open?id=1Eslg2Wy3orG41eywwm_O6qN4OQ3QN-bA
and from the equations of the drum 2, I get...
Homework Statement
A ball on the end of a string is whirled around in a horizontal circle of radius 0.250m. The plane of the circle is 1.06m above the ground. The string breaks and the ball lands 1.90m (horizontally) away from the point on the ground directly beneath the ball's location when...
Homework Statement
An ambulance driver is rushing a patient to the hospital. While traveling at 70 km/h, she notices the traffic light at the upcoming intersections has turned amber. To reach the intersection before the light turns red, she must travel 58 m in 2.5 s.
1.
What minimum...
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I have mind boggling problem, trying to distinguish between Dynamic reaction versus Coriolis acceleration of thin hoop.
Problem: A thin, hoop of mass m and radius r spins at the constant rate ω 1 about an axle...