Direct link to Teacher Mackenzie (UK)'s post Good, clear question. Direct link to Mursi Serag's post Quite late, but "flooring, Posted 6 years ago. Which was the first Sci-Fi story to predict obnoxious "robo calls"? If an object's velocity increases from zero to 6 m/s in 3s, what is the object's acceleration? I'm not quite sure about why the car slows down if the signs of velocity and acceleration are oppposite and why it speeds up when they have the same signs. Of course moving in a straight line in this context means moving away from the previous location of the rotational motion, so an observer has the impression of the ball moving away from the center, when the ball is as stated simply continuing his motion with the velocity it had at the time of release. All rights reserved. Direct link to laddhanishtha's post Can someone please give t, Posted 6 years ago. You see, Newton's laws only work in an inertial reference frame (a frame of reference that isn't accelerating). Direct link to Robby358's post As to why the sign of cen, Posted 4 years ago. Assuming rightward is positive, the velocity is positive whenever the car is moving to the right, and the velocity is negative whenever the car is moving to the left. centripetal actually means - towards the center .So centripetal force is not a new type of force .Any force which is acting towards center can be called as centripetal force. If false, replace the capitalized word to make it true. Direct link to RobinZhangTheGreat's post So when we accelerate, we, Posted 7 years ago. The ball is not a rocket. An object moves along a straight line path such that its velocity is given by V = (-2t^3 + 4t^2 + 5t - 7) m/s At t = 0, the object is located at x = 2 m. 1. Why xargs does not process the last argument? Has magnitude AND direction. (Select all that apply.) The car's average acceleration points due east. What is the difference between deadlock prevention and deadlock resolution? You'll get a detailed solution from a subject matter expert that helps you learn core concepts. True False Explain. PHY 183 Flashcards | Quizlet But in the case of a ball moving in circle of course its direction of motion changes with time, this must imply that the ball is subjected to a force (remember that a force $\vec{F}$ creates an acceleration $\vec{a}$ according to the second law of dynamics: $\vec{F}=m\vec{a})$. Thus the triangles are similar :). Direct link to Yisi's post can someone explain how t, Posted 3 years ago. (A) A constant force is being applied to it in the direction of motion. If the change is toward the positive direction, it's positive. If an object has a changing speed, its velocity must also be changing but if it has a changing velocity its speed in no necessarily changing. In a better drawn diagram, they'd be pointing to the center of the circle. g. free-fall acceleration. At t = 0 s it has its most negative position. Two layers of change! The speed of the particle is then the rate of change of s, \(\dfrac{ds}{dt}\) and the direction of the velocity is tangent to the circle. Remember that velocity is a vector, so this statement means that the object left alone would keep also the same direction of motion. Reasoning for both. A car travels 10 km in 5 minutes when its average velocity is 80 km/hr . If you're standing on the ground and look at the spinning ball, then the acceleration is inwards (centripital) but if you were to choose the ball as your reference frame, then direction of acceleration flips (centrifugal). What should I follow, if two altimeters show different altitudes? People think, If the acceleration is negative, then the object is slowing down, and if the acceleration is positive, then the object is speeding up, right? Wrong. The net force on the object must be zero. If you look at the first paragraph in that section, and click explain, there is an example including an armadillo, which I do not understand. Answer true or false The rate at which position changes with time is called acceleration. In other words, I can be changing my velocity at a high rate regardless of whether I'm currently moving slow or fast.