Physics: Chapter 3 Test

Graph 3 represents an object whose speed is decreasing to zero. This is because the graph starts with a positive slope, indicating an initial positive velocity. As time progresses, the slope becomes less steep, indicating a decrease in velocity. Finally, the graph levels off at the x-axis, indicating that the object has come to a stop and its speed is zero.

The football is traveling at a speed of 35 yards per second because it covers a distance of 42 yards in 1.2 seconds. To find the speed, we divide the distance by the time: 42 yards / 1.2 seconds = 35 yards per second.

Displacement is the correct answer because it refers to the change in position of an object in a specific direction. It takes into account both the distance traveled and the direction of travel, making it a more precise measurement than distance or position alone. Distance only measures the total length traveled, while position refers to the object's location without considering any change in direction. Therefore, displacement best describes the amount of change in a certain direction in the location of an object.

Graph 4 in Figure 3-1 represents an object whose speed is zero. This is because the graph shows a straight horizontal line, which indicates that the object is not moving. The slope of the line is zero, indicating that there is no change in position over time. Therefore, the object's speed is zero.

Graph 2 represents the displacement of the ball according to the description. The graph shows the ball being thrown vertically upward, reaching a maximum height, and then returning back to the surface of the Earth. The positive displacement indicates the upward motion, and the negative displacement indicates the downward motion. Thus, graph 2 accurately represents the motion of the ball as it goes up and comes back down.

Distance refers to the total length covered during a journey, regardless of the direction. It is a scalar quantity and does not take into account the specific path taken or any changes in direction. Distance only considers the magnitude of the displacement, making it the appropriate term to describe the total length of a journey without regard to direction.

The speed of an object is calculated by dividing the distance traveled by the time taken. In this case, the elk runs 15 kilometers in 0.75 hours. To find the speed, we divide 15 km by 0.75 hours, which equals 20 km/hr. Therefore, the speed of the elk is 20 km/hr.

Speed is a measure of how quickly an object gets from one place to another. It is a scalar quantity that only considers the magnitude of the object's motion, regardless of its direction. Speed is calculated by dividing the distance traveled by the time taken. Unlike displacement, which takes into account both the distance and direction of an object's change in position, speed focuses solely on the rate of change in position. Acceleration, on the other hand, measures the rate at which an object's velocity changes over time, while position refers to the specific location of an object.

Graph 2 represents an object whose speed is increasing because the slope of the graph is positive and becomes steeper over time. This indicates that the object is moving faster as time progresses.

Graph 1 in Figure 3-1 represents an object with non-zero uniform speed because the graph shows a straight line with a constant slope. This indicates that the object is moving at a constant speed without any changes in velocity.

The expression "per" in units such as miles per hour or meters per second indicates division. It represents the ratio between two quantities, where the numerator is measured in miles or meters and the denominator is measured in hours or seconds. This division is used to calculate the rate or speed at which something is happening or changing.

The term "position" refers to the location of an object. It is a specific point or place where the object is situated in relation to a reference point. Distance refers to the total length traveled by an object, while displacement refers to the change in position of an object in a particular direction. Therefore, "position" is the correct term that specifically indicates the location of an object.

The golfer walks at a rate of 7.20 feet per second. To find the time required to walk a distance of 612 feet, we divide the distance by the rate. 612 feet divided by 7.20 feet per second equals approximately 85 seconds.

Speed is defined as the rate at which an object covers distance over a specific period of time. It is commonly expressed as a ratio of the distance traveled to the time taken. This ratio allows us to compare the amount of distance covered with the time it took to cover that distance, providing a clear measure of how fast or slow an object is moving.

The correct answer is BC and DE. This can be determined by looking at the graph. The cart is moving with non-zero uniform speed during the time intervals BC and DE because the distance covered by the cart during these intervals is the same for each unit of time. In other words, the slope of the graph is constant during these intervals, indicating uniform speed.

The slope of a distance versus time graph represents the velocity of an object. Velocity is defined as the rate of change of displacement with respect to time. In the context of a distance-time graph, the slope indicates the rate at which the object is changing its position or the distance it covers per unit time.

The slope of a graph line is determined by calculating the change in the vertical values divided by the change in the horizontal values. This is because the slope represents the rate at which the vertical values change with respect to the horizontal values. By dividing the change in the vertical values by the change in the horizontal values, we can determine how steep or gradual the line is and the direction in which it is moving.

Distance is defined as the total amount of space traveled by an object. It can be calculated by multiplying the time taken to travel and the speed at which the object is moving. This is because distance is equal to the rate of speed multiplied by the time taken. Therefore, the correct answer is the product of time and speed.

If a Canada goose flies at an average speed of 66 miles per hour for 20 minutes, we can calculate the distance it will travel by converting the time to hours. Since there are 60 minutes in an hour, 20 minutes is equal to 20/60 = 1/3 hour. Therefore, the distance traveled is 66 miles per hour * 1/3 hour = 22 miles.

The dependent variable on the graph is speed because it is the variable that changes in response to the independent variable, which is not mentioned in the question. The other options, distance and acceleration, are not mentioned as dependent variables in the question. The last option, the slope of the speed vs. distance graph, is not a dependent variable but a measure of the relationship between speed and distance.