Velocity acceleration Definition and 21 Threads

For a particle moving in a straight line, if the velocity is zero for a time interval, the acceleration is zero at any instant within the time interval. I am told the above statement is true. If I look at the equations v = dx/dt a = dv/dt It looks like if the velocity is zero for a time...

I am not able to understand the following paragraph from my Physics textbook;

Derek Muller is the Veritasium YouTube channel host and he had a wager against UCLA professor Alexander Kusenko on whether a unpowered car going downwind can go faster than the wind. Derek Muller said it can go faster than the wind, while Alexander Kusenko said it only seems that way because...

Hi, I need to come up with a math model for a digital ignition system. I've been thinking about it and I think that I need to measure 2 things to be able to calculate when I have to start charging the coil. They are the angular velocity and the acceleration but how can I do it? the idea is to...

For part (a), which generic function would be used? either y = f(x) = ASin(2πft + ϕ) or y(x,t)−y0=Asin(2πft±2πx/λ+ϕ) ?? Furthermore how to find out max. speed & max. acceleration of a point on the string?? Any directions please

Homework Statement The graph shows the variation with time t of the acceleration a of an object (graph attached). What is the change in velocity of the object in the time interval 0 to 4s? Homework Equations a = v/t The Attempt at a Solution My initial answer was -8 m/s, by simply finding the...

Having a cylindrical iron container with wall thickness of 20 cm, and a total weight of 500 tons when filled with its cargo, how would you be able to calculate its required voltage and current input in a vertical railgun system (relative to the Moon's surface), with an exit acceleration of...

Homework Statement A rock that is thrown upward from a bridge with an initial velocity of 2.0 m/s. (Assume there is no air drag: a = -10m/s2). a) If the rock takes 4.0 s to hit the water below once the rock is released. What is the final velocity of the rock as it hits the water? b) How high...

Homework Statement A train travels a distance of 1,2 km between two stations with an average velocity of 43.2 km/h. During it's motion, at the time t1=40s it moved accelerated, then at time t2 it moved uniformly, then at t3=40s it moved uniformly slowed. Find the maximum velocity of the train...

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 Two baseballs are set in motion from the top of a 5 m tall tower. One is thrown straight down toward the ground with an initial velocity of 20 m/s. The second is thrown straight up toward the sky with an initial velocity of 20 m/s. How do their velocities compare when they...

Homework Statement Fc = mv^2/r represents the motion of a simple pendulum. Describe how this data could be graphed so that the gradient of a straight line could be used to determine the velocity of the object. Homework Equations Fc = mv^2/r The Attempt at a Solution I'm kinda stumped. I tried...

I thought i would do some digging into the wonderful world of magnets, and I found some things that... well are real head scratchers... I was wondering if anyone here could help me wrap my brain around non uniform acceleration. I'm trying to calculate velocity using distance and varying...

Homework Statement We did two trials she didn't really go over it. first trial (1m, 1.50 seconds), (1.30m, 2.00 seconds) (1.5, 3.22); second trial (1m, 1.45), (1,30m, 2.03), (1m, 1.46) The mass of the weighted object is 50 and 200 g for the one in the car. We measured how far the toy truck...

So I have 2 questions to answer for my physics class and I'm not quite sure what to do. Here are the two questions and I was wondering if someone could possibly point me in the right direction. I'm not asking for the answers I just kind of want a rough idea of where to start. Thank you 1. An...

Homework Statement m Homework EquationsThe Attempt at a Solution

I am having trouble solving this problem. Any assistance is greatly appreciated. Water is discharged from a pipeline at a velocity of v given by v=1192p^(1/2), where p is the pressure (in psi). If the water pressure is changing at a rate of 404 psi/second, find the acceleration (dv/dt) of the...

Homework Statement Hi am a physics beginner love it but seem to have issues with understanding Linear motion .. Anyway i have a question ..will be glad if could help . " A car moves along a road in such a way that the distance x ,traveled in a time t ,is given by x=a+bt(to the power 3)...

1. a solid sphere (I=0.4mr^2) of mass 1.5 kg and radius 15 cm moves down a 35 degrees incline 7m long. Assuming it started from rest, what is its angular velocity in rad/s at the bottom of the incline? a)71.27 b)32.25 c)49.98 d)61.69 3.i tried by plugging in the values and trying to...

In physics we are studying velocity acceleration and gravity. Either i am stupid or am not understanding this, but i just can't seem to understand the material. for example i don't know which formula to use for which story problem, for example(Please do not answer the problem) With a cruising...