Mechanics Questions 5 Winter 2018 Please read carefully and answer properly Question Title * 1. Your Name: Question Title The next three questions refer to a toy car which can move to the right or left along a horizontal line (the positive part of the distance axis). Assume that friction is so small that it can be ignored. A force is applied to the car. Choose the one force graph (A through H) for each statement below which could allow the described motion of the car to continue. You may use a choice more than once or not at all. If you think that none is correct, answer choice J. Question Title * 2. The car moves toward the right and is speeding up at a steady rate (constant acceleration). A B C D E F G H J Question Title * 3. The car moves toward the left (toward the origin) with a steady (constant) velocity. A B C D E F G H J Question Title * 4. The car moves toward the right, speeds up and then slows down. A B C D E F G H J Question Title * 5. A ball is fired by a cannon from the top of a cliff as shown in the figure below. Which of the paths would the cannon ball most closely follow? A B C D E Question Title Question Title * 6. A boy throws a steel ball straight up. Consider the motion of the ball only after it has left the boy's hand but before it touches the ground, and assume that forces exerted by the air are negligible. For these conditions, the force(s) acting on the ball is (are): a downward force of gravity along with a steadily decreasing upward force. a steadily decreasing upward force from the moment it leaves the boy’s hand until it reaches its highest point; on the way down there is a steadily increasing downward force of gravity as the object gets closer to the earth. an almost constant downward force of gravity along with an upward force that steadily decreases until the ball reaches its highest point; on the way down there is only a constant downward force of gravity. an almost constant downward force of gravity only. none of the above. The ball falls back to ground because of its natural tendency to rest on the surface of the earth. Question Title The positions of two blocks at successive 0.20-second time intervals are represented by the numbered squares in the figure below. The blocks are moving toward the right. Question Title * 7. Do the blocks ever have the same speed? No. Yes, at instant 2. Yes, at instant 5. Yes, at instants 2 and 5. Yes, at some time during the interval 3 to 4. Question Title The positions of two blocks at successive 0.20-second time intervals are represented by the numbered squares in the figure below. The blocks are moving toward the right. Question Title * 8. The accelerations of the blocks are related as follows: The acceleration of "a" is greater than the acceleration of " b". The acceleration of "a" equals the acceleration of "b". Both accelerations are greater than zero. The acceleration of "b" is greater than the acceleration of "a". The acceleration of "a" equals the acceleration of "b". Both accelerations are zero. Not enough information is given to answer the question. Question Title * 9. Despite a very strong wind, a tennis player manages to hit a tennis ball with her racquet so that the ball passes over the net and lands in her opponent's court. Consider the following forces: 1. A downward force of gravity. 2. A force by the "hit". 3. A force exerted by the air. Which of the above forces is (are) acting on the tennis ball after it has left contact with the racquet and before it touches the ground? 1 only. 1 and 2. 1 and 3. 2 and 3. 1, 2, and 3. Question Title * 10. A stone dropped from the roof of a single story building to the surface of the earth: reaches a maximum speed quite soon after release and then falls at a constant speed thereafter. speeds up as it falls because the gravitational attraction gets considerably stronger as the stone gets closer to the earth. speeds up because of an almost constant force of gravity acting upon it. falls because of the natural tendency of all objects to rest on the surface of the earth. falls because of the combined effects of the force of gravity pushing it downward and the force of the air pushing it downward. Done