Which formula is dimensionally consistent with an expression yielding a value for velocity? (a is acceleration, x is distance, and t is time)
1. v/t²
2. vx²
3. v²/t
4. ½at²
Note the expression: y = x². Which statement is most consistent with this expression?
1. a. if y doubles, then x quadruples
2. b. y is greater than x
3. c. if x doubles, then y doubles
4. d. if x doubles, then y quadruples
On planet Z, the standard unit of length is the foose. Ann the Astronaut is 5.90 feet tall on earth. She lands on planet Z and is measured to be 94 foosi tall. Her partner Rachael is 88 foosi tall. How tall is Rachael on Earth?
1. a. 5.2 feet
2. b. 5.5 feet
3. c. 5.8 feet
4. d. 6.3 feet
If the displacement of an object, x, is related to velocity, v, according to the relation x = Av, the constant, A, has the dimension of which of the following?
1. a. acceleration
2. b. length
3. c. time
4. d. area
The distance to the Andromeda Galaxy is estimated at about 2 × 106 light years. A light year is the distance traveled by light in one year; if the speed of light is 3×108 m/s, about how far is it from our galaxy to Andromeda? (1 year = 3.15×10⁷ s)
1. a. 10 × 10¹⁵ m
2. b. 1 × 1018 m
3. c. 2×1022 m
4. d. 6×1012 m
For which of the values below is x > x³?
1. a. x = -1.5
2. b. x = 0
3. c. x = 1.0
4. d. x = 1.5
Suppose an equation relating position, x, to time, t, is given by x = b t³ + c t⁴, where b and c are constants. The dimensions of b and c are respectively
1. a. T³, T⁴.
2. b. 1/T3, 1/T4.
3. c. L/T3, L/T4.
4. d. L2×T3, L2×T4.
Modern electroplaters can cover a surface area of 60.0 m² with one troy ounce of gold (volume = 1.611 cm3).What is the thickness of the electroplated gold?
1. a. 2.68×10^-8 m
2. b. 1.34×10-9 m
3. c. 1.67×10-6 m
4. d. 3.33×10-7 m
When NASA was communicating with astronauts on the moon, the time from sending on the Earth to receiving on the moon was 1.28 s. Find the distance from Earth to the moon. (The speed of radio waves is 3.00×108 m/s).
1. a. 240 000 km
2. b. 384 000 km
3. c. 480 000 km
4. d. 768 000 km
A circle has an area of 2.0 m². A second circle has double the radius of the first. The area of the second circle is _____ times that of the first.
1. a. 0.50
2. b. 2.0
3. c. 4.0
4. d. 8.0
A bird, accelerating from rest at a constant rate, experiences a displacement of 28 m in 11 s. What is the average velocity?
1. a. 1.7 m/s
2. b. 2.5 m/s
3. c. 3.4 m/s
4. d. zero
Two objects of different mass are released simultaneously from the top of a 20-m tower and fall to the ground. If air resistance is negligible, which statement best applies?
1. a. The greater mass hits the ground first.
2. b. Both objects hit the ground together.
3. c. The smaller mass hits the ground first.
4. d. No conclusion can be made with the information given.
A baseball is released at rest from the top of the Washington Monument. It hits the ground after falling for 6.0 s. What was the height from which the ball was dropped? (g = 9.8 m/s2 and assume air resistance is negligible)
1. a. 1.5 x 10² m
2. b. 1.8 x 102 m
3. c. 1.1 x 102 m
4. d. 2.1 x 102 m
A rock, released at rest from the top of a tower, hits the ground after 1.5 s. What is the speed of the rock as it hits the ground? (g = 9.8 m/s2 and air resistance is negligible)
1. a. 15 m/s
2. b. 20 m/s
3. c. 31 m/s
4. d. 39 m/s
A cheetah can run at approximately 100 km/hr and a gazelle at 80.0 km/hr. If both animals are running at full speed, with the gazelle 70.0 m ahead, how long before the cheetah catches its prey?
1. a. 12.6 s
2. b. 25.2 s
3. c. 6.30 s
4. d. 10.7 s
Human reaction time is usually about 0.20 s. If your lab partner holds a ruler between your finger and thumb and releases it without warning, how far can you expect the ruler to fall before you catch it? The nearest value is:
1. a. 4.0 cm
2. b. 9.8 cm
3. c. 16 cm
4. d. 20 cm
Norma releases a bowling ball from rest; it rolls down a ramp with constant acceleration. After half a second it has traveled 0.75 m. How far has it traveled after two seconds?
1. a. 1.2 m
2. b. 4.7 m
3. c. 9.0 m
4. d. 12 m
The value of an object's acceleration may be characterized in equivalent words by which of the following?
1. a. displacement
2. b. rate of change of displacement
3. c. velocity
4. d. rate of change of velocity
A 50 g ball traveling at 25.0 m/s is bounced off a brick wall and rebounds at 22.0 m/s. A high speed camera records this event. If the ball is in contact with the wall for 3.50 ms, what is the average acceleration of the ball during this time interval?
1. a. 13 400 m/s²
2. b. 6 720 m/s2
3. c. 857 m/s2
4. d. 20 m/s2
A ball is thrown vertically upwards at 19.6 m/s. For its complete trip (up and back down to the starting position), its average velocity is
1. a. 19.6 m/s
2. b. 9.80 m/s
3. c. 4.90 m/s
4. d. not given
In the case of constant acceleration, the average velocity equals the instantaneous velocity
1. a. at the beginning of the time interval
2. b. at the end of the time interval
3. c. half-way through the time interval
4. d. three-fourths of the way through the time interval
Which of the following is an example of a vector quantity?
1. a. velocity
2. b. temperature
3. c. volume
4. d. mass
When we subtract a velocity vector from another velocity vector, the result is:
1. a. another velocity
2. b. an acceleration
3. c. a displacement
4. d. a scalar
When we add a displacement vector to another displacement vector, the result is:
1. a. a velocity
2. b. an acceleration
3. c. another displacement
4. d. a scalar
A student adds two vectors with magnitudes of 200 and 40. Which one of the following is the only possible choice for the magnitude of the resultant?
1. a. 100
2. b. 200
3. c. 260
4. d. 40
A jogger runs halfway around a circular path with a radius of 60 m. What, respectively, are the magnitude of the displacement and distance jogged?
1. a. 60 m, 188 m
2. b. 120 m, 188 m
3. c. 0 m, 377 m
4. d. 120 m, 377 m
The first displacement is 6 m and the second displacement is 3 m. They cannot add together to give a total displacement of:
1. a. 2 m
2. b. 3 m
3. c. 6 m
4. d. 9 m
A baseball thrown from the outfield is released from shoulder height at an initial velocity of 29.4 m/s at an initial angle of 30.0° with respect to the horizontal. If it is in its trajectory for a total of 3.00 s before being caught by the third baseman at an equal shoulder height level, what is the ball's net vertical displacement during its 3-s trajectory?
1. a. 11.0 m
2. b. 9.80 m
3. c. 22.1 m
4. d. zero
A baseball is thrown by the center fielder (from shoulder level) to home plate where it is caught (on the fly at an equal shoulder level) by the catcher. At what point is the ball's speed at a minimum? (air resistance is negligible)
1. a. just after leaving the center fielder×s hand
2. b. just before arriving at the catcher×s mitt
3. c. at the top of the trajectory
4. d. speed is constant during entire trajectory
A baseball is thrown by the center fielder (from shoulder level) to home plate where it is caught (on the fly at shoulder level) by the catcher. At what point is the magnitude of the acceleration at a minimum? (air resistance is negligible)
1. a. just after leaving center fielder×s hand
2. b. just before arriving at catcher×s mitt
3. c. at the top of the trajectory
4. d. acceleration is constant during entire trajectory
A ball is rolled horizontally off a table with an initial speed of 0.24 m/s. A stopwatch measures the ball×s trajectory time from table to the floor to be 0.30 s. What is the height of the table? (g = 9.8 m/s2 and air resistance is negligible)
1. a. 0.11 m
2. b. 0.22 m
3. c. 0.33 m
4. d. 0.44 m
A ball is rolled horizontally off a table with an initial speed of 0.24 m/s. A stop watch measures the ball×s trajectory time from table to the floor to be 0.30 s. How far away from the table does the ball land? (g = 9.8 m/s2 and air resistance is negligible)
1. a. 0.055 m
2. b. 0.072 m
3. c. 1.2 m
4. d. 1.9 m
A rifle is aimed horizontally toward the center of a target 100 m away. If the bullet strikes 10 cm below the center, what was the velocity of the bullet? (Ignore air friction.)
1. a. 300 m/s
2. b. 333 m/s
3. c. 500 m/s
4. d. 700 m/s
A boat moves at 10.0 m/s relative to the water. If the boat is in a river where the current is 2.00 m/s, how long does it take the boat to make a complete round trip of 1000 m upstream followed by a 1000-m trip downstream?
1. a. 200 s
2. b. 203 s
3. c. 208 s
4. d. 250 s
Superguy is flying at treetop level near Paris when he sees the Eiffel Tower elevator start to fall (the cable snapped). His x ray vision tells him Lois LaTour is inside. If Superguy is 1.00 km away from the tower, and the elevator falls from a height of 240 m, how long does Superguy have to save Lois, and what must be his average speed?
1. a. 3.00 s, 333 m/s
2. b. 5.00 s, 200 m/s
3. c. 7.00 s, 143 m/s
4. d. 9.00 s, 111 m/s
A fireman, 50.0 m away from a burning building, directs a stream of water from a fire hose at an angle of 30.0° above the horizontal. If the initial speed of the stream is 40.0 m/s, at what height will the stream of water strike the building?
1. a. 9.60 m
2. b. 13.4 m
3. c. 18.7 m
4. d. 22.4 m
Vector A is 3 m long and vector B is 4 m long. The length of the sum of the vectors is
1. a. 5 m.
2. b. 7 m.
3. c. 12 m.
4. d. some value from 1 m to 7 m.
Acceleration due to gravity on the Moon×s surface is 1/6th that on Earth. An astronaut×s life support backpack weighs 300 lb on Earth. What does it weigh on the Moon?
1. a. 1 800 lb
2. b. 300 lb
3. c. 135 lb
4. d. 50 lb
Rita accelerates a 0.40-kg ball from rest to 9.0 m/s during the 0.15 s in which her foot is in contact with the ball. What average force does she apply to the ball during the kick?
1. a. 48 N
2. b. 72 N
3. c. 24 N
4. d. 60 N
A 70.0 kg man jumps 1.00 m down onto a concrete walkway. His downward motion stops in 0.0200 seconds. If he forgets to bend his knees, what force is transmitted to his leg bones?
1. a. 15 500 N
2. b. 7 010 N
3. c. 4 900 N
4. d. 3 500 N
A barefoot field goal kicker imparts a speed of 30 m/s to a football at rest. If the football has a mass of 0.50 kg and time of contact with the football is 0.025 s, what is the force exerted on the football?
1. a. 190 N
2. b. 380 N
3. c. 600 N
4. d. 900 N
An automobile of mass 2 000 kg moving at 30 m/s is braked suddenly with a constant braking force of 10 000 N. How far does the car travel before stopping?
1. a. 45 m
2. b. 90 m
3. c. 135 m
4. d. 180 m
A shot-putter moves his arm and the 7.0-kg shot through a distance of 1.0 m, giving the shot a velocity of 10 m/s from rest. Find the average force exerted on the shot during this time.
1. a. 175 N
2. b. 350 N
3. c. 525 N
4. d. 700 N
In the terminology a 500-N block, the 500-N refers to the block's
1. a. mass
2. b. force
3. c. weight
4. d. none of the above