Physics 111 Exam 1
If one inch is equal to 2.54 cm, express 9.68 inches in meters
0.246 m
Determine the length of the side of the right triangle labeled x
0.94 km
The figure shows three paths for a football kicked from ground level. Ignoring the air resistance, rank the paths according to the time it takes to land
1 = 2 = 3
Consider each of the following comparisons between various length units. Which one of these comparisons is false?
1 foot < 10 cm
Consider each of the following comparisons between various time units. Which one of these comparisons is false?
1 ns > 1000 µs
A car starts from rest on a circular track with a radius of 150 m. Relative to the starting position, what angle has the car swept out when it has traveled 150 m along the circular track?
1 radian
In making a movie, a stuntman has to jump from one roof onto another roof, located 2.0 m below. The buildings are separated by a distance of 2.5 m. What is the minimum horizontal speed that the stuntman must have when jumping from the first roof to have a successful jump?
3.9 m/s
A physics student standing on the edge of a cliff throws a stone vertically downward with an initial speed of 10.0 m/s. The instant before the stone hits the ground below, it is traveling at a speed of 30.0 m/s. If the physics student were to throw the rock horizontally outward from the cliff instead, with the same initial speed of 10.0 m/s, what is the magnitude of the velocity of the stone just before it hits the ground? Ignore any effects of air resistance.
30.0 m/s
A boat attempts to cross a river. The boat's speed with respect to the water is 12.0 m/s. The speed of the river current with respect to the river bank is 6.0 m/s. At what angle should the boat be directed so that it crosses the river to a point directly across from its starting point
30.0°
During the execution of a play, a football player carries the ball for a distance of 33 m in the direction 76° north of east. To determine the number of meters gained on the play, find the northward component of the ball's displacement
32 m
Determine the angle q in the right triangle shown
35.5°
Football A is kicked at a speed v at an angle of q with respect to the horizontal direction. If football B is kicked at the same angle, but with a speed 2v, what is the ratio of the range of B to the range of A
4
An airplane starts from rest at the end of a runway and accelerates at a constant rate. In the first second, the airplane travels 1.11 m. What is the speed of the airplane at the end of the second second?
4.44 m/s
A glacier is receding at a constant rate of 0.42 cm per day. After 3.0 years, by what length has the glacier receded? Express your answer in meters
4.6 m
Given the mathematical expression A = 3B, determine which of the following statements is true
B is three times smaller than A.
At a circus, two clowns, Bippy and Bobo, climb into identical cannons and are launched at identical initial velocities from the same starting height at the same instant of time. Bippy's cannon makes an angle of 55° angle with respect to the ground and Bobo's cannon makes an angle of 45° with respect to the ground. Both clowns land in a net parallel to the ground at height h. Which clown first, if either? Neglect air resistance.
Bobo
Complete the following statement: The ratio 1mg: 1kg is equal to
10^6
Vector has a horizontal component ax = 15.0 m and makes an angle q = 38.0° with respect to the positive x direction. What is the magnitude of ay, the vertical component of vector ?
11.7 m
What is the angle between the vectors A and -A when they are drawn from a common origin
180 degrees
An eagle takes off from a tree branch on the side of a mountain and flies due west for 225 m in 19 s. Spying a mouse on the ground to the west, the eagle dives 441 m at an angle of 65° relative to the horizontal direction for 11 s to catch the mouse. Determine the eagle's average velocity for the thirty second interval.
19 m/s at 44° below the horizontal direction
A turtle and a rabbit are to have a race. The turtle's average speed is 0.9 m/s. The rabbit's average speed is 9 m/s. The distance from the starting line to the finish line is 1500 m. The rabbit decides to let the turtle run before he starts running to give the turtle a head start. What, approximately, is the maximum time the rabbit can wait before starting to run and still win the race?
25 minutes
A train is traveling due east at a speed of 26.8 m/s relative to the ground. A passenger is walking toward the front of the train at a speed of 1.7 m/s relative to the train. Directly overhead the train is a plane flying horizontally due west at a speed of 257.0 m/s relative to the ground. What is the horizontal component of the velocity of the airplane with respect to the passenger on the train?
285.5 m/s, due west
Approximately how many seconds are there in a century
3.2 × 10^9 s
An airplane starts from rest at the end of a runway and accelerates at a constant rate. In the first second, the airplane travels 1.11 m. How much additional distance will the airplane travel during the second second of its motion?
3.33 m
A section of a river can be approximated as a rectangle that is 48 m wide and 172 m long. Express the area of this river in square kilometers.
8.26 × 10-3 km2
Consider the position versus time graph shown. Which curve on the graph best represents a car that is initially moving in one direction and then reverses directions
None of the curves represent a car moving in one direction then reversing its direction.
Newton's 3rd Law
Object A exerts a force on object B and object B exerts a force on object A of equal magnitude, But in the opposite direction.
Starting from rest, two objects accelerate with the same constant acceleration. Object A accelerates for three times as much time as object B, however. Which one of the following statements is true concerning these objects at the end of their respective periods of acceleration?
Object A will travel nine times as far as object B.
Which one of the following statements is true concerning scalar quantities?
Scalar quantities can be added to other scalar quantities using rules of ordinary addition.
In two-dimensional motion in the x-y plane, assuming any constant acceleration, what is the relationship between the x part of the motion to the y part of the motion?
The x part of the motion is independent of the y part of the motion.
At a circus, two clowns, Bippy and Bobo, climb into identical cannons and are launched at identical initial velocities from the same starting height at the same instant of time. Each clown lands in a net parallel to the ground at height h, but Bobo lands further away from his cannon than Bippy does from hers. Which clown, if either, lands with greater instantaneous velocity? Neglect any effects due to air resistance
They land with the same instantaneous velocity.
Inertial Reference Frame
This is when Newton's laws of Inertia (Motion) are valid.
A duck travels North East 90km from a pond, then turns 90deg and flies South East for 120km.
Using Pythagorean Theorem, Ans: R = 150km
When vectors A and B are added together they form vector C and these vectors satisfy the relationship A^2 + B^2 = C^2. Which statement is true for these vectors
Vectors A and B must be perpendicular
1.2.1. When we measure physical quantities, the units may be anything that is reasonable as long as they are well defined. It's usually best to use the international standard units. Density may be defined as the mass of an object divided by its volume. Which of the following units would probably not be acceptable units of density?
gallons/liter
A bicyclist is riding at a constant speed along a horizontal, straight-line path. The rider throws a ball straight up to a height a few meters above her head. Ignoring air resistance, where will the ball land? Ignore any effects of air resistance.
in the same hand that threw the ball
Displacement
it is a vector that points from an objects initial position to its final position. It has a magnitude that equals the shortest distance between the two positions. Path independent
When a football in a field goal attempt reaches its maximum height, how does its speed compare to its magnitude of initial velocity
it is less than its initial magnitude
Inertia
it resist acceleration, Mass - it is also how much stuff we have in our object
Two identical stones are dropped from a tall building, one after the other. Assume air resistance is negligible. While both stones are falling, what will happen to the vertical distance between them
it will increase
In the absence of an external force, a moving object will
move with constant velocity
Distance
the total distance covered. It is path dependent
Determine the length of the side of the right triangle labeled x
1.95 m
During a high school track meet, an athlete performing the long jump runs and leaps at an angle of 25° and lands in a sand pit 8.5 m from his launch point. If the launch point and landing points are at the same height, y = 0 m, with what speed does the athlete land?
10 m/s
A turtle, moving at a constant velocity of 0.9 m/s due south, is in a race with a rabbit, who runs at a moderate speed of 9 m/s. When the turtle is 45 m from the finish line, the rabbit begins taunting the turtle by running from the turtle to the finish line (without crossing it) and back to the turtle. The rabbit continues going back and forth between the turtle and the finish line until the turtle crosses the finish line. About how many meters does the rabbit travel as the turtle travels that last 45 m? Assume the rabbit always runs at 9 m/s and doesn't lose any time changing direction.
450 m
A cannon directed straight upward launches a ball with an initial speed v. The ball reaches a maximum height h in a time t. Then, the same cannon is used to launch a second ball straight upward at a speed 2v. In terms of h and t, what is the maximum height the second ball reaches and how long does it take to reach that height? Ignore any effects of air resistance
4h, 2t
a power boat, starting from rest, maintains a constant acceleration. after a certain time t, its displacement and velocity are r and v. at time 2t, what would be its displacement and velocity, assuming the acceleration remains the same?
4r and 2v
Given that one inch is equal to 25.4 mm. How many feet equal 21.0 m?
68.9 ft
The Normal Force
A NORMAL force FN or N is perpendicular to the surface. This is the force the surface exerts on the object.
Packages A and B are dropped from the same height simultaneously. Package A is dropped from an airplane that is flying due east at constant speed. Package B is dropped from rest from a helicopter hovering in a stationary position above the ground. Ignoring air friction effects, which of the following statements is true
A and B reach the ground at the same time; and they have the same velocity in the vertical direction.
A police cruiser is parked by the side of the road when a speeding car passes. The cruiser follows the speeding car. Consider the following diagrams where the dots represent the cruiser's position at 0.5-s intervals. Which diagram(s) are possible representations of the cruiser's motion
A or C only
Newton's 1st Law of Motion
An object at rest or in constant motion will stay at rest or in a constant motion UNLESS acted on by a NET Force.
You travel from 200m to 100m toward the classroom
Ans: -100m
Two identical ping-pong balls are selected for a physics demonstration. A tiny hole is drilled in one of the balls; and the ball is filled with water. The hole is sealed so that no water can escape. Each ball is shot horizontally from a gun with an initial velocity v0 from the top of a building. The following drawing shows several trajectories numbered 1 through 5. Which of the following statements is true
Both balls would follow trajectory 3.
Two cars travel along a level highway. An observer notices that the distance between the cars is increasing. Which one of the following statements concerning this situation is true
Both cars could be accelerating at the same rate.
Consider the position versus time graph shown. Which curve on the graph best represents a constantly accelerating car?
C
Which expression is false concerning the vectors shown in the sketch?
C = A + B
Cars A and B are moving away from each other as car A moves due north at 25 m/s with respect to the ground and car B moves due south at 15 m/s with respect to the ground. What are the velocities of the other car according to the two drivers?
Car A is moving due north at 40 m/s; and car B is moving due south at 40 m/s
A father and his five year old daughter are facing each other on ice skates. With their hands, they push off against one another. Which one of the following statements are true
Each experiences an acceleration that has a different magnitude.
Newton's Law of Universal Gravity
Every particle in the universe exerts an attractive force on every other particle in the universe.
Express the following statement as an algebraic expression: "There are 264 gallons in a one cubic meter container." Let G represent the number of gallons and M represent the number of one cubic meter containers
G = M/264
Free Fall
If only one force is acting on an object and that force is gravity, then the object is in Free Fall
In an air race, two planes are traveling due east. Plane One has a larger acceleration than Plane Two has. Both accelerations are in the same direction. Which one of the following statements is true concerning this situation?
In the same time interval, the change in the velocity of Plane One is greater than that of Plane Two.
Jackson heads east at 25 km/h for 20 minutes before heading south at 45 km/h for 20 minutes. Hunter heads south at 45 km/h for 10 minutes before heading east at 25 km/h for 30 minutes. Which driver has the greater average velocity, if either?
Jackson
Which of the following velocity vs. time graphs represents an object with a negative constant acceleration?
Negative linear slope
Sailors are throwing a football on the deck of an aircraft carrier as it is sailing with a constant velocity due east. Sailor A is standing on the west side of the flight deck while sailor B is standing on the east side. Sailors on the deck of another aircraft carrier that is stationary are watching the football as it is being tossed back and forth as the first carrier passes. Assume that sailors A and B throw the football with the same initial speed at the same launch angle with respect to the horizontal, do the sailors on the stationary carrier see the football follow the same parabolic trajectory as the ball goes east to west as it does when it goes west to east?
No, to the stationary sailors, the length of the trajectory appears longer as it travels west to east than when it travels east to west.
The right figure gives the velocity of a particle moving on an x-axis. Which of the following statements concerning the motion of the particle is false
The acceleration changes direction at v=0
A truck drives due south for 1.2 km in 1.5 minutes. Then, the truck turns and drives 1.2 km due west for 1.5 minutes. Which one of the following statements is correct
The average speed for the two segments is the same. The average velocity for the two segments is not the same.
A race car, traveling at constant speed, makes one lap around a circular track of radius r in a time t. The circumference of a circle is given by C = 2pr. Which one of the following statements concerning this car is true?
The average speed of the car is the same over any time interval.
A ball is thrown toward a wall, bounces, and returns to the thrower with the same speed as it had before it bounced. Which one of the following statements correctly describes this situation
The ball was accelerated during its contact with the wall because its velocity changed.
The graph below represents the speed of a car traveling due east for a portion of its travel along a horizontal road. Which of the following statements concerning this graph is true?
The car initially has a positive acceleration, but then it has a variable negative acceleration before it stops.
The radius of sphere A is one half that of sphere B. How do the circumference and volume of sphere B compare to sphere A
The circumference of B is 2 times that of A; and its volume is 8 times that of A.
In the morning, a bird is in Tampa, Florida. In the afternoon, the bird is near Orlando, Florida. Given this information, which one of the following statements best describes the relationship between the magnitude of the bird's displacement and the distance the bird traveled?
The distance traveled is either greater than or equal to the magnitude of bird's displacement.
In the right figure, the free body diagram of a diver in the water is shown. The buoyancy force is the force that the water exerts upward on the diver, which we call "action force" What is the "reaction force"
The downward force that the diver exerts on the water
Which one of the following situations involves a vector
The flock of Canadian Geese was spotted flying due south at 5 m/s
A ball is rolling down one hill and up another as shown. Points A and B are at the same height. How do the velocity and acceleration change as the ball rolls from point A to point B?
The horizontal component of the velocity is the same at points A and B, but the vertical component of the velocity has the same magnitude, but the opposite sign at B. The acceleration at points A and B is the same.
Instantaneous Velocity
The limit of the change in time as time goes to zero of the displacement / time
A motorcyclist is riding along a mountain trail that runs parallel to a road below. In fact the trail is 6 meters above the road. The motorcyclist then notices a flat bed truck directly below moving at the same speed and decides to drive off the trail, without changing speed. Fortunately, the motorcycle safely lands on the flatbed of the truck. What would the outcome have been if the trail was 12 meters above the road, but all other parameters remain the same?
The motorcycle would land on the flatbed of the truck as before.
An airplane is flying horizontally at a constant velocity when a package is dropped from its cargo bay. Assuming no air resistance, which one of the following statements is correct?
The package follows a curved path, but it is always vertically below the airplane.
John always paddles his canoe at constant speed v with respect to the still water of a river. One day, the river current was due west was moving at a constant speed that was close to v with respect to that of still water. John decided to see whether making a round trip across the river and back, a north-south trip, would be faster than making a round trip an equal distance east-west. What was the result of John's test?
The time for the north-south trip was greater than the time for the east-west trip.
At one particular moment, a subway train is moving with a positive velocity and negative acceleration. Which of the following phrases best describes the motion of this train? Assume the front of the train is pointing in the positive x direction.
The train is moving forward as it slows down
Two identical ping-pong balls are selected for a physics demonstration. A tiny hole is drilled in one of the balls; and the ball is filled with water. The hole is sealed so that no water can escape. The two balls are then dropped from rest at the exact same time from the roof of a building. Assuming there is no wind and air resistance can be neglected, which one of the following statements is true
The two balls reach the ground at the same time.
Which of the following about vectors is an accurate statement
the length of a vector arrow represents the magnitude of the vector
Newton's 2nd Law of Motion
When a net external force, F , acts on an object of mass, m, the resulting acceleration, a is directly proportional to the mass.
Given the following equation: y = cnat2, where n is an integer with no units, c is a number between zero and one with no units, the variable t has units of seconds and y is expressed in meters, determine which of the following statements is true.
a has units of meters per second per second (m/s2), but value of n cannot be determined through dimensional analysis.
A ball is thrown vertically downward. During the ball's flight, its velocity and acceleration vectors are
always in the same direction
A toy rocket is launched at an angle of 45° with a speed v0. If there is no air resistance, at what point during the time that it is in the air does the speed of the rocket equal 0.5v0?
at no time during the flight
The city of Denver is located approximately one mile (1.61 km) above sea level. Assume you are standing on a beach in Los Angeles, California, a distance of 830 miles (1300 km) at sea level; estimate the angle of the resultant vector with respect to the horizontal axis between your location in California and Denver.
between 0.06° and 0.10°
Complete the following statement: For an object moving at constant acceleration, the distance traveled
cannot be determined, even if the elapsed time is known
The drawing shows the position of a rolling ball at one second intervals. Which one of the following phrases best describes the motion of this ball?
constant velocity
Complete the following statement: For an object moving with a negative velocity and a positive acceleration, the distance traveled
decreases for each second that the object moves.
consider the position versus time graph shown in the right. Which curve on the graph best represents a motion with a constant positive velocity
positive linear slope
The list which contains only SI units
second, meter, kilogram
Suppose that a car traveling to the East ( + x direction) begins to slow down as it approaches a traffic light. Make a statement concerning its acceleration
the car is decelerating and its acceleration is negative
Which of the following ideas is true about projectile motion with no air resistance
the horizontal motion is independent of the vertical motion.
A passenger train starts from rest and leaves a station with a constant acceleration. During a certain time interval, the displacement of the train increases to three times the value it had at the start of that interval. During that same time interval, determine the increase in the train's velocity. Let v represent the speed of the train at the end of the time interval; and v0 represent the speed at the beginning of the interval.
v = 1.7v0
An object moves horizontally with a constant acceleration. At time t = 0 s, the object is at x = 0 m. For which of the following combinations of initial velocity and acceleration will the object be at x = -1.5 m at time t = 3 s
v0 = +1 m/s, a = -1 m/s
The slope of a positive versus time graph gives
velocity
In which one of the following situations can the equations of kinematics not be used
when the acceleration changes from moment to moment
Complete the following statement: In two-dimensional motion in the x-y plane, the x part of the motion and the y part of the motion are independent
whether or not there is an acceleration in any direction.
