Exam 2: Motion Along a Straight Line

The position of a particle is given by $x ( t ) = 23 t - 1.2 t ^ { 3 }$ , where x(t) is in meters and t is in seconds. The (positive) time when the particle has zero velocity is

A woman is running at 5.1 m/s to catch a bus parked at the bus stop. When she is 11 m from the bus, the bus leaves the stop with an acceleration of 1 m/s² (away from the woman). When the woman first catches the bus, how far away is she (or the bus) from the bus stop?

A body has a constant acceleration of +5 ft/s², an initial speed of -10 ft/s, and a time of travel of 4 seconds. The net displacement is

Two people, 100 m apart, begin walking toward each other. One person walks at 3 m/s and the other person walks at 2.3 m/s. The time (seconds) at which they will meet is

All of the following are valid (though perhaps unusual) units for speed except

A tourist starts along a path of total length L. He finds that in half the time allotted he has covered a distance of only L/3. This gives him an average speed of V₁. To complete the tour on schedule, his average speed for the remainder of the tour must be

A car traveling at an average speed of 25 m/s covers a distance of 900 km. The time required to travel this distance was

A runner, running in a straight line, travels 1.4 km in three minutes. The runner then turns around and runs back to her original position in four minutes. The average speed of the runner is

A vehicle travels for four hours at a speed of 54 m/s. The vehicle then travels for two hours at a speed of 47 m/s. The average speed of the vehicle during the entire six hours is

The average speed is computed by

A body has a constant acceleration of +5 ft/sec², an initial speed of -10 ft/s, and a time of travel of 4 seconds. The total distance covered is

We will always calculate the average speed correctly by simply taking half the sum of the initial and final speeds during the time interval for all of the following cases except

A car travels 80 km in one hour. The average speed of the car is

The mathematical relationship between the acceleration and the speed of a body is precisely the same as the mathematical relationship between

The average velocity of a body over some time interval is equal to the instantaneous velocity of the body whenever the acceleration of the body during that time interval is

For a falling body near the surface of the Earth (neglecting air drag), all of the following change with time except

The position of a particle along the x axis is given by $x ( t ) = 5 t + 3 t ^ { 2 }$ , where t is in seconds and x(t) is in meters. The velocity of the particle at time t = 5 seconds is

A woman is running at 5.1 m/s to catch a bus parked at the bus stop. When she is 11 m from the bus, the bus leaves the stop with an acceleration of 1 m/s² (away from the woman). The quickest (shortest) time at which the woman can catch the bus is

A runner, running in a straight line, travels 1.4 km in three minutes. The runner then turns around and runs back to her original position in four minutes. The average velocity of the runner is

Two people, 100 m apart, begin walking toward each other. One person walks at 3 m/s and the other person walks at 2.3 m/s. When they meet, the distance covered by the faster walker is