Physics Questions & Answers

Physics Questions & Answers A ball is rolling down one hill and up another as shown. Points A and B are at the same height. How do the velocity and acceleration change as the ball rolls from point A to point B? - CORRECT ANSWER- The horizontal component of the velocity is the same at points A and B, but the vertical component of the velocity has the same magnitude, but the opposite sign at B. The acceleration at points A and B is the same. A ball is thrown downward and its speed is v just before it strikes the ground. After the collision with the earth, it heads upward with a speed v. Which one of the following statements concerning this situation is true? - CORRECT ANSWER- Only the momentum of the earth is changed by the collision A ball is thrown toward a wall, bounces, and returns to the thrower with the same speed as it had before it bounced. Which one of the following statements correctly describes this situation? - CORRECT ANSWER- The ball was accelerated during its contact with the wall because its direction changed. A bicycle travels 141m along a circular track of radius 15m. What is the angular displacement in radians of the bicycle from its staring position? - CORRECT ANSWER- 9.4 rad A car travels at constant speed v up a hill from point A to point B, as shown in the diagram below. As the car travels from A to B, its gravitational PE - CORRECT ANSWER- Increases and it kinetic energy remains the same A car travels at constant speed v up a hill from point A to point B, as shown in the diagram below. As the car travels from A to B, its KE - CORRECT ANSWER- Decreases and its potential energy increases A girl is sitting on the edge of a merry-go-round at a playground as shown. Looking down from above, the merry-go-round is rotating clockwise. What is the direction of the girl's angular velocity? - CORRECT ANSWER- downward A meteor of mass M moves with constant speed v in circular orbits of radium R. Which of the following statements are true? - CORRECT ANSWER- Its angular speed is v/R Its tangential acceleration is zero The magnitude of its centripetal acceleration is constant A mountain climber pulls a supply pack up the side of a mountain at a constant speed. Which one of the following statements concerning this situation is false? - CORRECT ANSWER- The work done on the pack by gravity is zero joules A pendulum swings through a total of 28. If the displacement is equal on each side of the equilibrium position, what is the amplitude of this vibration? - CORRECT ANSWER- 14