-1
votes
0answers
29 views

An inclined pulley system [on hold]

M1 and M2 both are 400g. There is no friction and the pulleys are massless. I am trying to work out the acceleration on M2. I am unsure whether the acceleration should be: $a\space =Mg\space -\space ...
0
votes
1answer
46 views

Which moves faster in a time $t$: $A$ or $B$? [on hold]

Suppose we have two objects, $A$ and $B$, both made of the same substance. They also have the same shape (e.g. two spheres), but $A$ is larger and therefore more massive than $B$. Both $A$ and $B$ ...
1
vote
1answer
32 views

Moment of inertia help [on hold]

Okay so lets say I have a lever with 2 objects on it, object one and object 2. Object 1 has a mass of $m_1$ and is $r_1$ away from the fulcrum; object 2 has a mass of $m_2$ and is $r_2$ away from the ...
1
vote
0answers
23 views

Accelerating disk [on hold]

A disk of radius $R$ is accelerating to the right over a plane. At $t=0$ the speed and the acceleration of the axle are $v_1$ and $a_1$ what is the velocity and the acceleration of each point (1-4 ...
-3
votes
0answers
29 views

How to calcuate uniform circular motion? [on hold]

Given: Ideally, I maintain a speed of 265km/hr and 285 km/hr. Roughly, 73.6 m/s and 79m/s. I make a turn and experience around 4.5g's to 5.5g's, roughly 45 and 55 m/s^2, for about 7 seconds. I ...
0
votes
1answer
34 views

Catapult projectile with different mass [on hold]

We have a physics law. We made catapult and we have to launch a water balloon. However before that we have to know where the water balloon will fall. We don't have radars or stuff like that to ...
0
votes
0answers
49 views

How to describe the motion of a box initially at rest on a table rotating with an increasing angular speed? [on hold]

Consider the following diagram. A box is on a table that can move circularly and the box is connected by a string attached to the fixed bearing. At $t=0$, the box is at rest, the string of length ...
0
votes
0answers
11 views

Teeter Todder force of uplift [on hold]

What is the force of a 200lb man jumping from a three foot high elevation onto a four foot long teeter-todder with a four inch pivot point with a one hundred and thirty pound ma on the opposite ...
-1
votes
0answers
13 views

Motion in a straight Line [on hold]

A stone is projected from a height of 300m and at same time another stone is projected vertically upwards with a velocity of 100m/s Find when and where the two stones meet
3
votes
0answers
48 views

How do I treat the Lagrangian in the case of a rigid body?

Here's Exercise 1.11 from Goldstein's Classical Mechanics 3rd edition (the first one after having derived the Lagrangian basically): Exercise 1.11: Consider a uniform thin disk that rolls without ...
-1
votes
0answers
14 views

Angular velocity and linear velocity [on hold]

Define and EXPLAIN average angular velocity and acceleration. Define and EXPLAIN instantaneous angular velocity. Experiment was about throwing a cricket ball. the shoulder is the point of reference. ...
0
votes
1answer
19 views

With what speed must e.g. a car drive into a turn so it won't drift out? [on hold]

I am trying to figure out the following question: with what speed must e.g. a car drive into a turn so it won't drift out (if a turn is a circumference of a semicircle)? e.g. $r= 5 m$ $a_r= ...
0
votes
0answers
15 views

Falling with air resistance speed as a function of distance [on hold]

Starting at 0 velocity and falling with air resistance $-mkv$, find the relation between speed and the vertical distance that an object falls. I went through the problem to find the equation of motion ...
0
votes
0answers
13 views

Acceleration of the rope holding two objects(one heavier than other) with both objects on different inclines [on hold]

How do you find the acceleration of the rope and what would this process look like condensed into one big formula?
0
votes
1answer
33 views

Projectile motion with air resistance limit question [on hold]

I have the equation for the max height $h$ of a projectile launched directly upwards with speed $v_0$ and air resistance force $-mkv$. I am trying to calculate the limit as $h$ goes to ...
2
votes
3answers
146 views

What is the significance of clamping the center of the spring?

7. A block is hung on a spring, and the frequency $f$ of the oscillation of the system is measured. The block, a second identical block, and the spring are carried in the Space Shuttle to space. ...
-2
votes
1answer
24 views

Accelerating Tetrahedron [closed]

Four identical spheres are in contact with each other and form a tetrahedron. If acceleration of the top sphere is $a$, find the acceleration of the spheres on ground.
0
votes
1answer
56 views

Center of mass after explosion [closed]

How he treated the center of mass as if it is still in the same place , is not it supposed to change after explosion ? and is not explosion destroying the closed system? i mean it represents and ...
2
votes
1answer
90 views

Rolling a ball into a cone; what should the forces overall be?

This is my solution to finding angular displacement/velocity/acceleration on cone so far. Consider a cone, with an apex of half-angle $\psi$ pointing down, and a height of $h$. If I roll a ball into ...
0
votes
0answers
32 views

Plank stopping time (Continuation and Physical meaning)

A while back I asked this problem: "Plank stopping time" I thought it was solved, but now I have some questions about the solution. Problem: A plank of length $L$ and mass $m$ lies on a ...
1
vote
1answer
51 views

Simple Harmonic Motion homework [closed]

Suppose we have a rod of mass $m$ and length $l$ which is pivoted at center and two springs of spring constant $k$ are attached at opposite ends so that it performs simple Harmonic motion when ...
1
vote
0answers
93 views

Tension in a pulley system [closed]

In the question above, what I don't understand is how to calculate the tension in the second case (case in which the pulley is there). I realized after reading some questions, that the arrangement ...
1
vote
2answers
55 views

Pulling on a weakened rope - where will it tear?

Let's say I have a rope of 10m length and it is weakened in 3 spots: at 2.5m, at 5m and at 7.5m. Weakened means that if enough tension is applied it will tear at these points (all points are equally ...
-1
votes
0answers
31 views

Ramp and Cart physics lab help [closed]

So we have a physics lab where we took a cart and rolled it down an inclined plane (100 cm) and off of varying heights (3 - 12 cm). We were supposed to record those variables and also time how long it ...
-1
votes
0answers
52 views

Southern deflection when free fall [closed]

While I do my mechanics homework, I meet the problem that I can't understand the solution. The problem is 10.13 from Marion book. I cannot understand why the pure gravitational component should be ...
0
votes
1answer
22 views

Confusion about horizonally projected body

DESCRIBED IN IMAGE CLEARLY In the text book, I got the initial velocity of x-component initial velocity Vxi, Vxi = Vi cos(0); (0 = zero) but what if it is like the picture i showed, first it was ...
1
vote
1answer
63 views

Two masses on frictionless table with one string connecting both masses on ground and the other string [closed]

From Morin's Introduction to Classical Mechanics page 342: A solid cylinder of mass $m$ and radius $r$ lies flat on frictionless horizontal table, with a massless string running halfway around ...
1
vote
1answer
49 views

Frequency of Oscillations about Circular Orbit [on hold]

I'm trying to figure out the frequency of small oscillations about the basic circular path of a mass at the end of a spring, being spun around a table. I understand that the spring will stretch out a ...
1
vote
0answers
57 views

How to show circular orbit as a precessing ellipse

A uniform distribution of dust in the solar system adds to the gravitational attraction of the sun on the planet an additional force linear in $r$ where m is the mass of the planet, k is a constant ...
0
votes
0answers
11 views

Question on a variant of Atwood machine with strings unwinding in one side

The figure is standard Atwood machine except that for the right object string tension acts on the left side of the object, and strings unwind from the object. No slip condition on a rolling ...
1
vote
1answer
24 views

How to find the maximum height with a loss of 5 J of energy due to air drag [closed]

Can someone please help me to figure out how to use the 5J of energy into my equation for the maximum height. I know that the maximum height is given by, $$h_{max}={(v_f-v_i)^2 \over 2g}$$ but I'm ...
0
votes
3answers
59 views

Finding maximum height of projectile motion using potential/kinetic energy

I'm having some difficulty understanding how to find the maximum height using conservation of force. This is the picture I'm looking at: and this is how you find it: $$\begin{align*} ...
4
votes
1answer
145 views

Why am I wrong about this dynamics question?

I disagree with the answer to this homework question. Here it goes. The coefficient of static friction is 0.60 between the two blocks in figure. The coefficient of kinetic friction between the ...
1
vote
2answers
201 views

Why did I get this dynamics question wrong? [closed]

I'm wondering as to why I got this physics question wrong, despite it being quite simple in nature. I believe that I missed something while working on the problem. Basically, the question involves ...
4
votes
3answers
726 views

Acceleration of an object dropped inside an accelerating elevator

A stone is released from an elevator going up with acceleration of $g/2$. What is the acceleration of the stone just after the release? The answer is $g$. Shouldn't the stone carry the acceleration ...
0
votes
1answer
49 views

What is the final velocity of a stone dropped out of a rising balloon? [closed]

A balloon is starting from the ground has been ascending vertically at uniform velocity for 4 sec and a stone let to fall from it reaches the ground in 6 sec. Find the velocity with which the stone ...
0
votes
1answer
89 views

Description of the motion of the COM of a system of charged particles moving in a magnetic field

I recently came across a problem where an electrically neutral particle is at rest in a uniform magnetic field. The particle now splits into two charged particles of equal mass $m$; charge and mass ...
0
votes
2answers
47 views

Calculate average speed of projectile with air resistance

There's a project that I'm working on that been bugging me for awhile. The project involves this senario: A projectile is released at 1000 feet per second and moves in a straight line infinitely ...
0
votes
0answers
29 views

Free body diagram of mechanisms

The image below shows a mechanism with 2 pin joints. On one of the pin joints, there is a torsional spring that exerts a torque $M_s = \kappa \theta$ (rest state is at $\theta = 0$). A force $F$ is ...
2
votes
0answers
27 views

What will be the time taken by a stone to reach the ground if it is thrown with velocity $v$? [closed]

I was studying from my reference book and I got this question. I tried solving it by finding the total distance n average velocity but it didn't work please help me out.
-2
votes
0answers
20 views

To find angular speed of a rotating body [duplicate]

A body moving with uniform angular acceleration covers 100 pi (rad)in first 5 s. Its angular speed at the end of 5 s (in rad/s) is?? My ans is 40 pi, but according to the answer given in my book ...
1
vote
2answers
68 views

Change of kinetic energy in a two particle collision

A problem I am working on proceeds as follows: A billiard ball of mass $M$ is initially at rest on a horizontal frictionless table. Another ball of mass $m < M$ and velocity $\mathbf{v}$ in ...
0
votes
2answers
28 views

Cylinder falling down the edge of a table [closed]

Suppose, a cylinder is placed on its lateral side at the edge of a table, carefully, so that the slightest push makes it fall from the table. We give it a gentle push. And it begins to fall. How is ...
1
vote
1answer
33 views

Accelerated wedge [closed]

Consider the following figure, where a mass $m$ is placed on a wedge which is accelerated to the right ($\vec a$) which could be negative. The coefficient of friction between the mass and the wedge ...
1
vote
0answers
39 views

At time $t=0$, what are the magnitude and direction of the perpendicular component of dp/dt? [closed]

In the dark in outer space, you observe a glowing ball of known mass 4.6 kg moving in the xy plane at constant speed in a circle of radius 7 m, with the center of the circle at the origin (< 0, 0, ...
1
vote
1answer
67 views

Tangential acceleration [duplicate]

If you are spinning an object using a mass-less string with constant speed in a vertical circle, and when the object is at an angle with the vertical, what happens to the component of weight in the ...
1
vote
0answers
59 views

Tension problem for rotating object? [closed]

when an object (tied to a massless string) is moving in a vertical circle with constant speed, does it have tangential acceleration when it is at some angle (theta) from the vertical? I am assuming ...
3
votes
1answer
59 views

Moments of vibrating string

I have to calculate first 10 moments for vibrating string with damping, but I don't know how to do it. I read about moments and in definition they mention linear system $$x'=Ax+Bu, \qquad y=Cx$$ with ...
1
vote
0answers
15 views

If a nozzle that converges from an inside diameter of 5cm to 3.5cm carries a gas at a VFR of 0.10 m^3/s, what is the change in average velocity? [closed]

If a circular nozzle that converges from an inside diameter of 5 cm to 3.5 cm carries a gas at a volume flow rate of $0.10 m^3/s$, what is the change in average velocity of the gas? (A nozzle being a ...
0
votes
2answers
63 views

Time for launched object to reach point in space

I am attempting to calculate the time required for an object launched perpendicular to the surface of the earth at escape velocity to reach an arbitrary point in space (neglecting rotational velocity, ...