Uniform Circular Motion - General Physics - Solved Past Paper, Exams of Physics

Download Uniform Circular Motion - General Physics - Solved Past Paper and more Exams Physics in PDF only on Docsity! 1. (20 pts) a) (5 pts) An object is moving in uniform circular motion (i.e. the speed of the object is constant). Is the centripetal acceleration constant? Why or why not? Acceleration is a vector, so if the direction changes, the acceleration is changing. The centripetal acceleration is always towards the center of the circle, but that direction changes as the object moves around the circle. Thus the centripetal acceleration is changing. So the answer to this question is it is not constant. b) (5 pts) Ignoring air friction, does the acceleration of a ball that has been thrown at an angle change during its flight? Why or why not? During flight the ball is in free-fall. The only acceleration is that due to gravity, which is constant. Thus the acceleration of the ball does not change. c) (5 pts) Three forces are acting on an object that sum to zero. Explain whether or not this is an isolated object. In order for an object to be isolated, it must NOT be interacting with anything else. There are three interactions going on here. Thus this is not an isolated object even though the forces add to zero. d) (5 pts) An object accelerates up and to the left. In what direction is the net force on this object, or is it even possible to say with the limited information given here? ~F = m~a If you know the direction of the acceleration ~a, then the force must be in the same direction, because multiplying a vector by a (positive) scalar results in another vector of a different length but in the same direction.