What should I do? Because I have two possibilities. I have ##0=5+at## so ##-5/t =a##. But then I can also say that the acceleration is a negative because it is stopping, so I can write it like ##0=5-kt## and then ##5/t =k##
The first doubt that comes to my mind is "I have to determine the acceleration with respect to what?", because the problem doesn't tell. Then, I have some problems when having to plug the data in the formula of acceleration. ##\vec a_B=0## because the origin isn't accelerated, ##\vec{\dot...
So my problem isn't actually finding the components, but knowing if the initial approach I took is correct. So what I did was:
At first I found that at the same instant, ##x_{B/A}=10500 m## so then I wrote the equation of motion for plane B respect to A:
so $$\vec a_{B/O}- \vec a_{A/O}=\vec...
So what I did was at first consider the case the kid is below the branch, so that x=0,t=0, then I thought that the lenght L of the rope should be ##L=2h## because we know the radius from the branch to the kid is just ##x^2+y^2=r^2## and when x=0, y=h. So then I wrote the motion equations for the...
So I know that ##a_t = \frac{dv}{dt}=-ks## and ##\frac{dv}{dt}=v\frac{dv}{ds}## then: $$v dv=-ks ds \rightarrow (v(s))^2=-ks^2+c$$ and using my initial conditions it follows that: $$(3.6)^2=c \approx 13$$ and $$(1.8)^2=13-5.4k \rightarrow k=1.8 \rightarrow (v(s))^2=13-1.8s$$
What bothers me is...
I tried to workout the problem but I find motion in different coordinates systems a bit weird at the moment, so only thing I could do is realise that the x component of ##\vec r(t)## is: $$vt +x_0$$ but for simplicity we will use the initial condition ##x_0=0## so that ##t_0## is the moment the...
So ##T+U=\frac{1}{2}m(\dot{x}^{2}+\dot{y}^{2})-mgy=constant##. If I derive this with respect to ##t##
$$\dot{x}\ddot{x}+\dot{y}\ddot{y}-g\dot{y}=0$$
Then I use ##\dot{y}=\dot{x}\frac{dy}{dx},\ddot{y}=\ddot{x}\frac{dy}{dx}+\dot{x}^{2}\frac{d^{2}y}{dx^{2}}##
to get...
I've calculated the potential energy at the top of the halfpipe, before the boarder drops in:
PE = 39.5 kg * 9.8 m/s^2 * 3.66 m = 1416 J
Since the boarder would have no potential energy and all kinetic energy at the bottom of the halfpipe,
KE = 1/2mv^2 = 1416 J
1/2 (39.5 kg) (v^2) = 1416 J
So...
So there are two cases:
a). free fall (straight forward for me)
b). ladder rotating and jumping off in last moment (I am interested in trying to understand this case)
I believe I should take into account momentum at the time the man hits the ground in both cases? The smaller, the better. Or...
Hello. I have just started studying physics. Can someone explain to me how can I type in formulas here using Tex for nicer formatting?
I suppose the force is F = ma.
Question is: what is a?
The starting throw angle is not mentioned, I suppose this task has to be related to gravity. All I know...
To find vx
vx = dx/t = 3.86 m/1.5 s= 2.573 m/s
To find Ek
Ek = ½mvx²= ½(79.4)(2.573)²= 262.8 J
W = FnetΔd
Fnet = 262.8 J/ 3.86 m = 68 N
He hits him with a force of 68N
Hello,
1) Suppose I throw a ball with a force ##F=ma##, the instant it leaves my hand, does it have the same acceleration ##a## added to it accelerations due to "ambient" forces (air resistance, gravity..)?
2) If I am right about 1), doesn't my hand already carry the acceleration/deceleration...
I have a strange question. It's strange because I don't need a correct answer. I need an answer that seems correct and leads to predictable results. I'm making a multiplayer computer game where the players fire cannons in outer space. The cannon shells will move through the gravitational fields...
Hi
I am learning kinematics. Topics include inertia tensors, cosine matrices, quaternions, Euler angles etc... To learn these topics well, I want to try working on something a bit more difficult than just the underlying math. That will probably keep me more motivated.
So, I am looking for...
1. A stone is thrown vertically downwards from the observation deck of the CN Tower, 400 m above the ground, with a velocity of 12 m/s [down].
A) How long will it take the stone to reach the ground ?
B) How fast will it be going when it hits the ground ?
I just got into physics, so I’m not...
Hi, I need help with this problem:
1. Homework Statement
Condition: an object has to move from point A to point B in the least time possible. The distance between the points is L. The object can accelerate (decelerate) with a fixed acceleration ##a## or move with a constant speed.
What maximum...
1. Homework Statement
A baseball is hit into the air, nearly vertically, with a speed of 27 m/s. When it comes down, the ballplayer catches it in his glove. Air resistance (drag) is actually fairly important for a baseball in flight, but for now let’s assume it is negligible.
(a) How high...
1. Homework Statement
My problem has two parts.
1) We have two point masses ##m,M##. and there is another mass ##m_1## between them.They are all aligned in a line. Mass ##M## is moving with speed ##u_1## toward ##m_1## and after collision and all other masses are not moving. we want to find...
Hi, I'm currently taking Chemistry 101 and came across this equation that seems to contradict what I've learned before. I don't know the name of it, but here is the equation and its implication.
Now another equation we have learned is the Arrhenius equation, which is as follows:
If I...
I would like to measure time period of very short periods of electricity flow in the range of micro seconds or even smaller;can someone tell me me a device that can help me do this?
I'm a little confused with the application of laws of motion on a man climbing a rope. Suppose a man of mass Mg is climbing a rope with an acceleration a. Rope is massless. Now if look through the frame of the piece of rope held by the man, there is a force Mg downward by man, ma downward...
1. Homework Statement
Two cars are facing each other on a long straight airport runway. They are initially separated by a distance of 1 km. Car A begins to accelerate towards the other car at a uniform 0.5 ms^-2. Ten seconds later car B begins to move towards the other car with a uniform...
1. Homework Statement
An electron and a proton are each placed at rest in an electric ﬁeld of 687 N/C. What is the velocity of the electron 56.5 ns after being released? Consider the direction parallel to the ﬁeld to be positive. The fundamental charge is 1.602×10−19 C, the mass of a proton is...
1. Homework Statement
A flat cushion of mass m is released from rest at the corner of the roof of a building, at height h. A wind blowing along the side of the building exerts a constant horizontal force of magnitude F on the cushion as it drops as shown in the figure below. The air exerts no...
1. Homework Statement
Two blocks of mass m1 = 3.00 kg and m2 = 6.00 kg are connected by a massless string that passes over a frictionless pulley (see the figure below). The inclines are frictionless.
Image - https://www.webassign.net/serpse9/5-p-049.gif
The inclined plane is shaped like a...
1. Homework Statement
Raindrops fall from a broken gutter at 1.0 s intervals to the ground , 19.6 m below
Neglecting air resistance and taking g as 9.81 calculate
the time for each drop to reach the ground
velocity of the drops as they reach the ground
speed of drop at the height of 14.7 m...
1. Homework Statement
"Based on the following data, determine if the driver who crashed was driving over the speed limit"
The relevant data given is:
-A 2002 Volvo t-bones a truck in an alley with a speed limit of 20km/h
-An eyewitness heard tires screech, then a loud bang, and also said...
1. Homework Statement
I'm simulating a warehouse (in Unity) where forklifts and other vehicles transport stuff from point A to point B. The routes are modeled as a graph with vertices and edges. Every transport is saved as a task in a backend system with the relevant data such as starting time...