The rate of change of velocity of a body per unit of time.

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2
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1answer
74 views

Is there a gravitational radiation reaction force?

As you may know, the linearized relativity theory (or gravitoelectromagnetism), obeys equations analogous to Maxwell's equations in electrodynamics. These equations in ED result in the troubling ...
1
vote
1answer
39 views

Find the height and the velocity of the object [closed]

A bolt is detached from the lower part of an elevator cabin that is ascending with velocity 6meters/second and for 3 seconds comes to the point from where the elevator started to ascend. Find: in ...
0
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2answers
50 views

Why do riders feel forced down into their seats at the bottom of the first drop on a rollercoaster?

I am trying to figure out what forces an $80.0kg$ rider travelling at $110.0km/h$ ($30.56m/s$) would experience when at the bottom of the first drop on a rollercoaster where the radius of the ...
7
votes
2answers
593 views

How many Gs are my clothes experiencing in my washer? [closed]

During a spin cycle I got curious: How many Gs are at play in my simple washing machine? We can assume the drum is 50 cm wide and spins at 1500 rpm.
1
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0answers
40 views

Will the flash light accelerate in space? [duplicate]

As we know from school physics course light has pressure. So my question is will flash light accelerate in space in the direction opposite to light emission? If not, then will flash light with ...
2
votes
1answer
98 views

calculation of electrical power required drive a toy car [closed]

i wanted to put a electrical motor into a toy car. i want to use an optimum motor with correct RPM (i know that with fixed power, higher RPM mean less torque). so here it goes. i have a toy car with ...
-1
votes
3answers
64 views

Suppose I apply a force to a ball that can then only be slowed down by gravity or, perhaps, relativity. What happens to the ball? What would I see? [closed]

Suppose I'm on planet Earth. I have a ball that, once set in motion, can only be slowed down or stopped by gravity. What will happen to this ball? What would I (an observer on Earth) see? Here's what ...
-1
votes
1answer
36 views

Velocity and acceleration (as vectors) in a straight line

A student is trying to determine the acceleration of a feather as she drops it to the ground. If the student is looking to achieve a positive velocity and positive acceleration, what is the most ...
-1
votes
1answer
63 views

Is gravitational acceleration truly independent of mass?

I am doing Newtonian Physics. Correct me if I am wrong: So two objects always exert equal forces on each other(Newtons Third). So for example the same gravitational force that the earth exerts on a ...
0
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0answers
39 views

Force exerted by pulley on ceiling

I read in my book that when a pulley is accelerating it exerts more force on the ceiling than when it is still. I know the derivation and I can mathematically prove it but I'm unable to get my head ...
1
vote
1answer
66 views

Calculate position with position depending force

I have an equation that says $a(t)= \alpha * s(t)+\beta$ where $a$ ist the acceleration, $\alpha$ and $\beta$ are constants, $s$ is position and $t$ the time. My question is how to get the resulting ...
0
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1answer
26 views

How would you solve for this system while it's accelerating? [closed]

So I'm trying to solve for this system with two weights: m1 and m2, with m2 hanging off of m1, which is hanging by two ropes off a ceiling (connected to top of m1) one rope(t1) angled 50 degrees and ...
0
votes
1answer
91 views

How to determine when to decelerate to reach a destination at 0 velocity?

(Sorry, not sure whether this belongs here on the Physics StackExchange or the Math StackExchange.) I'm creating a computer game in which there is a computer-controlled car that needs to travel along ...
0
votes
1answer
65 views

Metric of an accelerated reference frame (without gravitation)

If we look at a flat Minkowski space-time (without any gravitation) an choose an accelerated frame of reference, what happens to the metric tensor is it still in Minkowski coordinates or will he be ...
1
vote
1answer
50 views

Is there a principal difference in acceleration from an impulse and the free fall of a body in the orbit around a gravitational mass?

Especially taking in account that acceleration need a force which leads to some conversion of energy. This is not the case for orbital motion, such a acceleration does not convert energy. That seems ...
1
vote
3answers
134 views

Acceleration - Constant force vs force for an instant

I am reading about Newton's second law, and I am slightly confused. So I think I get that $F=ma$ can be used to find acceleration. I am struggling between two scenarios: constant force acting over a ...
0
votes
2answers
93 views

Obtaining Velocity from Acceleration

I'm following a research paper (PDF via RG), part of which is about using the accelerometer of a smartphone to assist the user's positioning via WLAN. Accelerometer is used to determine if the user ...
0
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0answers
68 views

Position from acceleration, or acceleration from position, to track an object moving the speed of sound

I'm working on a project that involves tracing the motion of a fast-moving object (approx the speed of sound) through a fairly defined trajectory. Would it be more accurate to measure the position of ...
0
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2answers
247 views

Need help understanding angular acceleration due to gravity

The question asks what the angular acceleration of an uniform disc of radius $R$ rotating about an axis passing through its edge if it is released from rest with its center of mass at the same height ...
0
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0answers
84 views

Circular Motion: Rubber Stopper Lab

During a lab I was doing involving uniform circular motion, we had to spin a rubber stopper horizontally via a rope. At the bottom of the rope, there was some weights. I have to answer this question ...
0
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3answers
49 views

Do I need to have a force acting in an opposite direction to feel the force of acceleration?

Suppose I'm in a rocket, accelerating away from the Earth. While I'm accelerating away from the Earth in the rocket, I can feel the force of acceleration. Now, let's suppose we take away the Earth, ...
1
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3answers
76 views

Initial speed in homework problem [closed]

This is a homework question. I tried to solve it, but failed. I had to translate this question, so please forgive me if it is poorly worded. In this question you can ignore the atmospheric ...
1
vote
2answers
111 views

The acceleration of the centre of mass [closed]

Given two balls that are thrown straight up in the air at a speed of $40 \:\mathrm{m/s}$, $0.10 \:\mathrm{s}$ apart. One ball is twice the mass of the other. The heavier ball is thrown second. I'm ...
0
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2answers
39 views

Acceleration vs. Velocity

Since acceleration is a change in velocity or a change in direction how can in reality velocity exist since a straight line does not exist except in Euclidean geometry? Any movement from one point to ...
1
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3answers
154 views

Force of an object “skidding”?

Let's say I put the brakes on really suddenly in a car that was moving at 40mph. If I know how much force it takes to break the adhesion of the wheels, how do I find the force the car is exerting? ...
-1
votes
2answers
59 views

Why is only one end at rest when a rope is attached to a cube? [duplicate]

I know there is something wrong in the way I think about physics generally, but I don't know what it is. Suppose there is a cube with a hook on one face and a rope attached to that hook (see diagram)....
2
votes
1answer
88 views

Calculating mass of an orbiting body with force and acceleration

I'm new to physics, and it's a lot to take in- but there is a problem that I really can't seem to wrap my head around- finding the mass of an orbiting body, like an asteroid. I've looked around a lot ...
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2answers
63 views
1
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1answer
118 views

A heavy crate (mass m) is placed inside the flatbed of a truck but not tied down

A heavy crate (mass m) is placed inside the flatbed of a truck but not tied down. As the truck pulls away from a stop sign the crate remains in place and does not slide on the truck bed. What force ...
0
votes
1answer
51 views

Motion in one dimension

Here is a question which is not really hard and from my lecture PHYS101. How come does the first statement is false and second is true? Thank you. 1. If a car is slowing down, its acceleration must ...
0
votes
1answer
169 views

Why does mass not matter on how quickly an object falls? [duplicate]

I've seen all the mathematical proofs and physics demonstrations in vacuums. However, for example, if a hammer falls to the Earth it falls very quickly. But, it can be interpreted another way. The ...
0
votes
1answer
55 views

What does dimensionless quantity 'number of $g$' mean?

I am doing data analysis in which I found a quantity named "no. of $g$". I don't know what it means or what is its usage. Look at the image below. I want to know the meaning and usage of "no. of $...
2
votes
1answer
79 views

Why can we model a body to have a center of mass?

I accept that bodies have a center of mass. I also accept that if I were to suspend a body by only supporting it at its center of mass, then the body wouldn't rotate. In the scenario that we suspend a ...
0
votes
1answer
44 views

Solve the inverse function of the solution to a varying acceleration problem ODE

Suppose there are two positive charges $A$ and $B$, both with equal mass $m$ and the same charge quantity $q$. The initial distance between $AB$ is $R$; and the initial velocity of $B$ relatively to $...
0
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3answers
609 views

Pendulum's motion is simple harmonic motion

For a pendulum's motion to be simple harmonic motion (S.H.M.) is it necessary for a pendulum to have small amplitude or S.H.M. can be produced at large amplitudes as well? If it is really necessary ...
0
votes
1answer
44 views

What happens to centripetal acceleration if you change speed while rounding a corner? [closed]

What happens to centripetal acceleration if you change speed while rounding a corner?
0
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1answer
70 views

For a particle moving in a circle,can $a_t\neq 0$ and $a_r= 0$? [duplicate]

I know for a fact that if a particle is moving in a circle such that the value of radial acceleration is non-zero and the value of tangential acceleration is zero ,then it can be classified as ...
0
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1answer
298 views

Spring-block system, simple harmonic motion, time period

In the case of simple harmonic motion of spring block system, why time period of the simple harmonic motion of the block is independent of acceleration of the system (spring-block system)?
0
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3answers
96 views

Why is centripetal acceleration called acceleration

Centripetal acceleration has a direction towards the center of the rotating object and if the magnitude of the speed of rotation remains same, then why do we call it an centripetal acceleration? Doesn'...
2
votes
2answers
47 views

Exertion of force due to spin of Earth

If Earth were to spin at a different speed would I be experiencing a different weight?
0
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1answer
39 views

Determine time over known distance, constant acceleration and starting speed [closed]

Problem: I have an object covering a specific distance (say 100m) at a starting speed (say 10m/s) and a constant acceleration of 1m/s/s. Which equation can I use determine how long it will take the ...
0
votes
0answers
39 views

Galileo proved wrong? [duplicate]

Galileo stated that objects dropped from the same height will hit the ground at the same time, that the rate of gravity is constant for all objects no matter the mass. But I think there is a flaw in ...
0
votes
2answers
57 views

Why does a block 2 on a oscillating block 1 start sliding at the maximum acceleration?

A block of mass $ m_{1} $ is oscillating horizontally with another block on it of mass $ m_{2} $. There's friction "k" between both blocks, so the thing is why the second mass starts sliding at the ...
2
votes
3answers
229 views

Terminal velocity and distance traveled with constant but limited power

I'm trying to model how far to move an object over time according to a power applied resisted by friction. So maybe... an object accelerates at a certain rate until the power provided can no longer ...
1
vote
1answer
99 views

What really is mass?

I was always taught that mass was how much matter something is made of, but I recently read that it is how resistant an object is to acceleration; as such, you could add mass to an object by ...
1
vote
2answers
587 views

Half-atwood machine with accelerating pulley

This is a follow-up to my previous question, in which I am now trying to calculate the acceleration of the cart (as before, the block surfaces are frictionless). The mass $m_2$ is attached to $M$ via ...
1
vote
2answers
69 views

Exercise pulleys and accelerations [closed]

The system shown has ideal massless pulleys and no friction. The pulleys 1 and 2 are fixed and the pulley 3 is mobile. The mass m2 is rigidly attached to the center of the pulley 3 by a support ...
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6answers
1k views

What is the acceleration at the top most point of a ball’s journey vertically upward?

When i shoot a ball vertically upward, it’s velocity is decreasing. So there is acceleration. -9.8m/s^2. I’ve read that at the top most point, the acceleration is STILL 9.8 m/s^2 where v=0 . The ...
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votes
1answer
110 views

What is the value of the Universe's acceleration? [closed]

Please read this http://www.researchgate.net/publication/282157370_VALUE_OF_THE_UNIVERSE%27S_ACCELERATION Your ideas are welcome.
0
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2answers
95 views

Calculating Acceleration

I'm having problems calculating acceleration for the following variables. I would have thought it would be extremely straight forward, except I am getting two different answers and do not know which ...