Gilfoil Test
If the velocity of an object is zero at some point, then its acceleration must also be zero at that point.
False
Two objects are dropped from a bridge, an interval of 1.0 s apart. Air resistance is negligible. During the time that both objects continue to fall, their separation
increases
When a ball is thrown straight up with no air resistance, the acceleration at its highest point
is downward
You drive 6.0 km at 50 km/h and then another 6.0 km at 90 km/h. Your average speed over the 12 km drive will be
less than 70 km/h.
If the velocity versus time graph of an object is a horizontal line, the object is
moving with zero acceleration.
A moving body must undergo a change of
position
Consider a deer that runs from point A to point B. The distance the deer runs can be greater than the magnitude of its displacement, but the magnitude of the displacement can never be greater than the distance it runs.
true
The slope of a position versus time graph gives
velocity
A confused dragonfly flies forward and backward in a straight line. Its motion is shown on the following graph of horizontal position vs. time t. What is the average velocity of the dragonfly for the time interval from t = 0 s to t = 8 s?
0 m/s
A runner runs around a track consisting of two parallel lines 96 m long connected at the ends by two semicircles with a radius of 49 m. She completes one lap in 100 seconds. What is her average velocity?
0 m/s
If a car is traveling at an average speed of 60 kilometers per hour, how long does it take to travel 12 kilometers?
0.2 hour
A dog is running in a straight line to catch a ball. Its motion is shown on the following graph of horizontal position vs. time .
0.25 m/s
A dog is running in a straight line to catch a ball. Its motion is shown on the following graph of horizontal position vs. time . What is the average velocity of the dog between the times t = 2 st = 6 s?
0.25 m/s
An airplane needs to reach a forward velocity of 203.0 km/h to take off. On a 2000-m runway, what is the minimum uniform acceleration necessary for the plane to take flight if it starts from rest?
0.79 m/s2
An airplane needs to reach a forward velocity of 203.0 km/h to take off. One a 2000-m runway, what is the minimum uniform acceleration necessary for the plane to take flight if it starts from rest?
0.79 m/s^2
A monkey climbs vertically on a vine. Its motion is shown on the following graph of vertical position vs. time
1.5 m/s
A monkey climbs vertically on a vine. Its motion is shown on the following graph of vertical position vs. time What is the instantaneous speed of the monkey at time t = 8 s?
1.5 m/s
The data table above lists the position of an object over a 6 second interval. What was the the average velocity of the object during this time period?
1.7 m/s
A runner completed the 100.-meter dash in 10.0 seconds. His average speed was
10.0 m/s
An instrument is thrown upward with a speed of 15 m/s on the surface of planet X where the acceleration due to gravity is 2.5 m/s2 and there is no atmosphere. How long does it take for the instrument to return to where it was thrown?
12
A water rocket can reach a speed of 75 m/s in 0.050 seconds from launch. What is its average acceleration? (in units of m/s2)
1500 m/s^2
A stone is thrown with an initial upward velocity of 7.0 m/s and experiences negligible air resistance. If we take upward as the positive direction, what is the velocity of the stone after 0.50 s?
2.1 m/s
A car travels 90. meters due north in 15 seconds. Then the car turns around and travels 40. meters due south in 5.0 seconds. What is the magnitude of the average velocity of the car during this 20.-second interval?
2.5 m/s
A student on an amusement park ride moves in a circular path with a radius of 3.5 meters once every 8.9 seconds. The student moves at an average speed of
2.5 m/s
A student on an amusement park ride moves in acircular path with a radius of 3.5 meters once every 8.9 seconds. The student moves at an average speed of
2.5 m/s
Arthur and Betty start walking toward each other when they are 100 m apart. Arthur has a speed of 3.0 m/s and Betty has a speed of 2.0 m/s. How long does it take for them to meet? (in seconds)
20 seconds
A car starts from rest and accelerates uniformly at 3.0 m/s2 toward the north. A second car starts from rest 6.0 s later at the same point and accelerates uniformly at 5.0 m/s2 toward the north. How long after the second car starts does it overtake the first car?
21 s
A jet plane is launched from a catapult on an aircraft carrier. In 2.0 s it reaches a speed of 42 m/s at the end of the catapult. Assuming the acceleration is constant, how far did it travel during those 2.0 s?
42 m
If a car accelerates at a uniform 4.0 m/s2, how long will it take to reach a speed of 80 km/hr, starting from rest? (answer unit is in seconds)
5.6 seconds
A ball is thrown straight up with a speed of 36 m/s. How long does it take to return to its starting point, assuming negligible air resistance?
7.3s
A ball is thrown downward from the top of a building with an initial speed of 25 m/s. It strikes the ground after 2.0 s. How high is the building, assuming negligible air resistance?
70
Which of the following situations is impossible?
An object has constant non-zero velocity and changing acceleration.
Which of the following quantities has units of a displacement? (There could be more than one correct choice.)
40 km southwest -186,000 mi
Which of the following graphs represent an object having zero acceleration?
graphs a and b
A car is moving with a constant speed of 20. meters per second. What total distance does the car travel in 2.0 minutes?
2400 m
A car starts from rest and accelerates at a steady 6.00 m/s2. How far does it travel in the first 3.00 s?
27.0 m
In a drill during basketball practice, a player runs the length of the 30 meter court and back. The player does this three times in 60 seconds. The average speed of the player during the drill is
3.0 m/s
An airplane increases its speed at the average rate of 15 m/s2. How much time does it take to increase its speed from 100 m/s to 160 m/s?
4.0
A test rocket at ground level is fired straight up from rest with a net upward acceleration of 20 m/s2. After 4.0 s, the motor turns off but the rocket continues to coast upward with insignificant air resistance. What maximum elevation does the rocket reach?
490 m
A baseball player runs 27.4 meters from the batter's box to first base, overruns first base by 3.0 meters, and then returns to first base. Compared to the total distance traveled by the player, the magnitude of the player's total displacement from the batter's box is
6.0 m shorter
A motorist makes a trip of 180 miles. For the first 90 miles she drives at a constant speed of 30 mph. At what constant speed must she drive the remaining distance if her average speed for the total trip is to be 40 mph?
60 mph
Two cars, A and B, are 400. meters apart. Car A travels due east at 30. meters per second on acollision course with car B, which travels due west at 20. meters per second. How much time elapses before the two cars collide?
8
Two cars, A and B, are 400. meters apart. Car A travels due east at 30. meters per second on a collision course with car B, which travels due west at 20. meters per second. How much time elapses before the two cars collide?
8.0s
Car A, moving in a straight line at a constant speed of 20. meters per second, is initially 200 meters behind car B, moving in the same straight line at a constant speed of 15 meters per second. How far must car A travel from this initial position before it catches up with car B?
800 m
On a highway, a car is driven 80. kilometers during the first 1.00 hour of travel, 50. kilometers during the next 0.50 hour, and 40. kilometers in the final 0.50 hour. What is the car's average speed for the entire trip?
85 km/hr
A student said "the displacement between my dorm and the lecture hall is 1 kilometer." Is he using the correct physical quantity for the information provided? What should he have called the 1 kilometer?
Distance
The area under a curve in a velocity versus time graph gives
displacement.
If the acceleration of an object is zero, then that object cannot be moving
false
A 10-kg rock and 20-kg rock are dropped from the same height and experience no significant air resistance. If it takes the 20-kg rock a time T to reach the ground, what time will it take the 10-kg rock to reach the ground?
T
Under what condition is average velocity equal to the average of the object's initial and final velocity?
The acceleration is constant
A rock from a volcanic eruption is launched straight up into the air with no appreciable air resistance. Which one of the following statements about this rock while it is in the air is correct?
The acceleration is downward at all points in the motion.
Suppose that an object is moving with a constant velocity. Which statement concerning its acceleration must be correct?
The acceleration is equal to zero.
Suppose that a car traveling to the west begins to slow down as it approaches a traffic light. Which of the following statements about its acceleration is correct?
The acceleration is toward the east.
Suppose that an object travels from one point in space to another. Make a comparison between the magnitude of the displacement and the distance traveled by this object
The displacement is either less than or equal to the distance traveled.
Two objects are thrown from the top of a tall building. One is thrown up, and the other is thrown down, both with the same initial speed. What are their speeds when they hit the street? Neglect air resistance.
They are traveling at the same speed.
An object is moving with constant non-zero velocity in the +x direction. The velocity versus time graph of this object is
a horizontal straight line
An object is moving with constant non-zero acceleration in the +x direction. The velocity versus time graph of this object is
a straight line making an angle with the time axis.
An object is moving with constant non-zero velocity in the +x direction. The position versus time graph of this object is
a straight line making an angle with the time axis.
The slope of a velocity versus time graph gives
acceleration
One car travels 40. meters due east in 5.0 seconds, and a second car travels 64 meters due west in 8.0 seconds. During their periods of travel, the cars definitely had the same
average speed