John goes for a run. From his house, he jogs north for exactly 5.0 min at an average speed of 8.0 km/h. He continues north at a speed of 12.0 km/h for the next 30.0 min. He then turns around and jogs south at a speed of 15.0 km/h for 15.0 min. Then he jogs south for another 20.0 min at 8.0 km/h. He walks the rest of the way home. How many kilometers does John jog in total?

Answer: 13.1 km

A man starts his car from rest and accelerates at 2 m/s^2 for 2 seconds. He then continues at a constant velocity for 11 seconds until he sees a tree blocking the road and applies brakes. The car, decelerating at 2 m/s^2 finally comes to rest. Which of the following graphs represents the motion correctly?

Answer: graph looks like a trapezoid

Moustapha Jones drives east at 100 km/hr for 3 hours then back west at 80 km/hr for 1.5 hours. Which pair of answers gives his average speed and average velocity

Answer: 93.3 km/hr, 40 km/hr east

In the graph above (same as #6) a toy rolls from +3 m to +5 m. Which of the following statements is true?

Answer: xi = +3 m

In the graph above what is the correct description of any location to the left of the zero? (graph shows a number line for position from 0 to 10)

Answer: negative change of displacement

Which of the following units is the SI unit of velocity?

Answer: meter per second

Which of the following situations represents a negative displacement? (Assume positive position is measured vertically upward along a y-axis.)

Answer: A cat jumps from a tree limb to the ground

What is the speed of an object at rest?

Answer: 0.0 m/s

Which of the following is a pair of vector quantities?

Answer: Velocity--Displacement

A car is moving with a uniform speed of 15.0 m/s along a straight path. What is the distance covered by the car in 12.0 minutes?

Answer: 1.08 x 10 ^1 km

A pilot drops a bomb from a plane flying horizontally at a constant speed. Neglecting air resistance, when the bomb hits the ground the horizontal location of the plane will

Answer: be over the bomb

A plane flying horizontally at a speed of 50.0 m/s and at an elevation of 160 m drops a package. Two seconds later it drops a second package. How far apart will the two packages land on the ground?

Answer: 100 m

A bullet is fired horizontally, and at the same instant a second bullet is dropped from the same height. Ignore air resistance. Compare the times of fall of the two bullets.

Answer: They hit at the same time.

A stone is thrown horizontally from the top of a tower at the same instant a ball is dropped vertically. Which object is traveling faster when it hits the level ground below?

Answer: the stone

When a football in a field goal attempt reaches its maximum height, how does its speed compare to its initial speed?

Answer: It is less than its initial speed.

A ball thrown at an original speed of 8.0 m/s at an angle of 35 degrees above the horizontal. What is the speed of the ball when it returns to the same horizontal level?

Answer: 8.0 m/s

An Olympic athlete throws a javelin at four different angles above the horizontal, each with the same speed: 30 degrees, 40 degrees, 60 degrees, and 80 degrees. Which two throws cause the javelin to land the same distance away?

Answer: 30 and 60 degrees

At what angle should a water-gun be aimed in order for the water to land with the greatest horizontal range?

Answer: 45 degrees

Which of the following does not exhibit parabolic motion?

Answer: a flat piece of paper released from a window

Which is the path of a projectile (in the absence of friction)?

Answer: a parabola

Which of the following is not an example of projectile motion?

Answer: a hot-air balloon drifting toward Earth

Which of the following is an example of projectile motion?

Answer: a thrown baseball

Which of the following is the motion of objects moving in two dimensions under the influence of gravity?

Answer: projectile motion

Two balls are thrown horizontally. Ball C is thrown with a force at 20 N, and ball D is thrown with a force of 40 N. Assuming all other factors are equal, ball D will fall toward the ground

Answer: at the same rate as ball C

A player kicks a football at an angle of 30.0 degrees above the horizontal. The football has an initial velocity of 20.0 m/s. Find the horizontal component of the velocity and the maximum height attained by the football.

Answer: 17.3 m/s, 5.10 m

A ball is thrown horizontally from a hill 29.0 m high at a velocity of 4.00 m/s. Find the distance between the base of the hill and the point where the ball hits the ground.

Answer: 9.73 m

A soldier throws a grenade horizontally from the top of a cliff. Which of the following curves best describes the path taken by the grenade?

Answer: Parabola

The path of a projectile through space is called its:

Answer: trajectory

Two horizontal forces act on a 5.0-kg mass. One force has a magnitude of 8.0 N and is directed due north. The second force toward the east has a magnitude of 6.0 N. What is the acceleration of the mass?

Answer: 2.0 m/s^2 at 53 degrees N of E

A stack of books rests on a level frictionless surface. A force F acts on the stack, and it accelerates at 3.0 m/s2. A 1.0 kg book is then added to the stack. The same force is applied, and now the stack accelerates at 2.0 m/s2. What was the mass of the original stack?

Answer: 2.0 kg

Sue and Sean are having a tug-of-war by pulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's force if the rope accelerates toward Sue at 2.0 m/s2?

Answer: 5.0 N

What is the mass of an object that weighs 250 N on the surface of the Earth where the acceleration due to gravity is 9.80 m/s2?

Answer: 25.5 kg

If you push a 4.0-kg mass with the same force that you push a 10-kg mass from rest,

Answer: The 4.0 kg mass accelerates 2.5 times faster than the 10-kg mass

A sled weighing 100.N is held in place on a frictionless 20.0° slope by a rope attached to a stake at the top. The rope is parallel to the slope. What is the normal force of the slope acting on the sled?

Answer: 94 N

A change in the gravitational force acting on an object will affect the object's?

Answer: Weight

The magnitude of the gravitational force acting on an object is

Answer: Weight

A hockey stick hits a puck on the ice. Identify the action-reaction pair in the situation?

Answer: The stick exerts a force on the puck; the puck exerts a force on the stick

A hammer drives a nail into a piece of wood. Identify an action-reaction pair in this situation

Answer: The hammer exerts a force on the nail; the nail exerts a force on the hammer

Newton's third law of motion involves the interactions of

Answer: Two objects and two forces

The statement by newton that for every action there is an equal and opposite reaction is which of his laws of motion

Answer: Third

A net force of 6.8 N accelerates a 31kg scooter across a level parking lot. What is the magnitude of the scooters acceleration?

Answer: .22 m/s^2

According to Newton's second law, when the same force is applied to two objects of different masses:

Answer: The object with greater mass will experience a smaller acceleration, and the object with less mass will experience a greater acceleration

Which statement about the acceleration of an object is correct?

Answer: The acceleration of an object is directly proportional to the net external force acting on the object and inversely proportional to the mass of the object

If a nonzero net force is acting on an object, then the object is definitely

Answer: Being accelerated

As an object falls toward earth

Answer: The upward acceleration of earth is negligible because of its large mass

A single force acts on an object. The components of this force act along the + x-axis and the y-axis. The single force that will bring the object into equilibrium has components that act along the

Answer: -x axis and +y axis

A car goes forward along a level road at constant velocity. The additional force needed to bring the car into equilibrium is

Answer: Zero

A late traveler rushes to catch a plane, pulling a suitcase with a force directed 30 degrees above the horizontal. If the horizontal component of the force on the suitcase is 60.6 N, what is the force exerted on the handle?

Answer: 70.0 N

Which of the following is the tendency of an object to maintain its state of motion?

Answer: Inertia

A length of force vector represents all of the following except

Answer: Forces exerted by the object

A newton is equivalent to which of the following quantities?

Answer: Kg m/s^2

What causes a moving object to change direction

Answer: Force

Which of the following statements does NOT describe force

Answer: Force causes objects at rest to remain stationary

Which of the following is the cause of acceleration?

Answer: Force

You are pushing a rock along level ground and making the rock speed up. How does the size of the force you exert on the rock compare with the size of the force the rock exerts on you? The force you exert

Answer: Is the same size as the force the rock exerts on you

A 1500-kg car can accelerate from rest to 72 km/h in 8.0 s. What is the net force acting on the car to cause this acceleration?

Answer: 3.8 N

A 6.0-kg wooden block is pulled across a carpet with a force of F = 36 N. The block begins at rest and accelerates to a velocity of 0.25 m/s in 0.50 s. What is the force of friction acting on the block?

Answer: 33 N

The relationship between force and acceleration is

Answer: direct linear

Which graph best describes the movement of an object on which no new force is exerted

Answer: Linear Distance vs. Time Graph

Which of the following system of forces provides the blocks the highest net force?

Answer: ---> l"""l <--- 54 N

A mass is attached to a vertical spring and bobs up and down between points A and B. Where is the mass located when its potential energy is a minimum?

Answer: midway between A and B

A mass on a spring undergoes SHM. When the mass passes through the equilibrium position, its instantaneous velocity

Answer: is maximum

For a system in simple harmonic motion, which of the following is the number of cycles or vibrations per unit of time?

Answer: frequency

Consider a 20.0-kg pendulum clock that keeps good time. If the clock is moved to a location where it weighs 74 N, how many minutes will the minute hand move in 1 h?

Answer: 38

Doubling only the spring constant of a vibrating mass-and-spring system produces what effect on the system's mechanical energy?

Answer: increases the energy by a factor of two

A mass is attached to a vertical spring and bobs up and down between points A and B. Where is the mass located when its potential energy is a maximum?

Answer: at either A or B

Doubling only the amplitude of a vibrating mass-and-spring system produces what effect on the system's mechanical energy?

Answer: increases the energy by a factor of four

A mass is attached to a vertical spring and bobs up and down between points A and B. Where is the mass located when its kinetic energy is a maximum?

Answer: midway between A and B

A vertical spring has a mass hanging from it, which is displaced from the equilibrium position and begins to oscillate. At what point does the system have the least potential energy?

Answer: at the equilibrium point

In simple harmonic motion, the acceleration is proportional to

Answer: the displacement

Vibration of an object about an equilibrium point is called simple harmonic motion when the restoring force is proportional to

Answer: displacement

A mass M is attached to a spring with spring constant k. When this system is set in motion with amplitude A, it has a period T. What is the period if the amplitude of the motion is increased to 2A?

Answer: T

What is the spring constant of a spring that stretches 2.00 cm when a mass of 0.600 kg is suspended from it?

Answer: 294 N/m

A mass attached to a spring vibrates back and forth. At maximum displacement, the spring force and the

Answer: acceleration reach a maximum

A 0.50-kg mass is attached to a spring of spring constant 20 N/m along a horizontal, frictionless surface. The object oscillates in simple harmonic motion and has a speed of 1.5 m/s at the equilibrium position. What is the total energy of the system?

Answer: 0.56J

A mass on a spring undergoes SHM. It goes through 10 complete oscillations in 5.0 s. What is the period?

Answer: 0.50s

For a system in simple harmonic motion, which of the following is the time required to complete a cycle of motion?

Answer: period

For a mass hanging from a spring, the maximum displacement the spring is stretched or compressed from its equilibrium position is the system's

Answer: amplitude

A simple pendulum swings in simple harmonic motion. At maximum displacement,

Answer: the acceleration reaches a maximum.

A mass is attached to a vertical spring and bobs up and down between points A and B. Where is the mass located when its kinetic energy is a minimum?

Answer: at either A or B

In simple harmonic motion, the speed is greatest at that point in the cycle when

Answer: the magnitude of the acceleration is a minimum.

Doubling only the amplitude of a vibrating mass-and-spring system produces what effect on the system's mechanical energy?

Answer: increases the energy by a factor of four

How are frequency and period related in simple harmonic motion?

Answer: they are inversely related

The work done to move a spring away from its equilibrium position is equal to

Answer: the potential energy of the spring

A mass M is attached to a spring with spring constant k. When this system is set in motion with amplitude A, it has a period T. What is the period if the mass is doubled to 2M?

Answer: sqrt2 t

Doubling only the spring constant of a vibrating mass-and-spring system produces what effect on the system's mechanical energy?

Answer: increases the energy by a factor of two 

What happens when a periodic driving force is applied at a frequency close to the natural frequency of the system?

Answer: The system will resonate and unless some energy is lost the amplitude of the vibrations will increase until the system breaks.

If you take a given pendulum to the Moon, where the acceleration of gravity is less than on Earth, the resonant frequency of the pendulum will

Answer: decrease

The velocity of a mass attached to a spring is given by v = (1.5 cm/s) sin(ωt + π/2), where ω = 3.0 rad/s. What is the corresponding expression for x?

Answer: x = -(0.50 cm) cos(ωt + π/2)

A mass attached to a spring vibrates back and forth. At the equilibrium position, the

Answer: velocity reaches a maximum

Which of the following features of a given pendulum changes when the pendulum is moved from Earth's surface to the moon?

Answer: the restoring force

Which of the following is not an example of approximate simple harmonic motion?

Answer: a ball bouncing on the floor

A mass on a spring undergoes SHM. When the mass is at maximum displacement from equilibrium, its instantaneous acceleration

Answer: is a maximum

Which of the following are characteristics of a mass in simple harmonic motion?

Answer: 

I. The motion repeats at regular intervals.

II. The motion is sinusoidal.

III. The restoring force is proportional to the displacement from equilibrium

A 0.30-kg mass is suspended on a spring. In equilibrium the mass stretches the spring 2.0 cm downward. The mass is then pulled an additional distance of 1.0 cm down and released from rest. Write down its equation of motion.

Answer: y = (0.01 m) cos (22.1 t)

The total mechanical energy of a simple harmonic oscillator is

Answer: constant

A mass m hanging on a spring has a natural frequency f. If the mass is increased to 4m, what is the new natural frequency?

Answer: 0.5f

Doubling only the mass of a vibrating mass-and-spring system produces what effect on the system's mechanical energy?

Answer: produces no change

What happens when a periodic driving force is applied at a frequency close to the natural frequency of the system?

Answer: The system will resonate and unless some energy is lost the amplitude of the vibrations will increase until the system breaks.

Tripling the displacement from equilibrium of an object in simple harmonic motion will change the magnitude of the object's maximum acceleration by what factor?

Answer: 3

In simple harmonic motion, the speed is greatest at that point in the cycle when

Answer: the magnitude of the acceleration is a minimum.

By what factor should the length of a simple pendulum be changed in order to triple the period of vibration?

Answer: 9

What is the treatment of H. ducreyi?

Answer: Treatment is either erythromycin or trimethoprim-sulfamethoxazole (TMP-SMX).

What sexually transmitted disease (STD) is caused by Haemophilus ducreyi?

Answer: Chancroid, characterized by a painful genital ulcer and often localized lymphadenitis

How is M. catarrhalis infection treated?

Answer: Almost all strains produce β-lactamase, so commonly prescribed antibiotics include amoxicillin-clavulanate, second-and third-generation oral cephalosporins, trimethoprim-sulfamethoxazole, and azithromycin.

What diseases does Moraxella catarrhalis cause?

Answer: Otitis media and sinusitis in children (third most common cause in the United States). Bronchitis and pneumonia in older people with chronic obstructive pulmonary disease (COPD) or underlying conditions

How are these transmitted?

Answer: Ehrlichia chaffeensis: through the tick Amblyomma americanum (lone star tick) and is classically associated with the white-tailed deer

Anaplasma phagocytophilum: through ixodid ticks (same as Lyme disease)

How do cells infected with these organisms appear on microscopic examination?

Answer: Ehrlichia chaffeensis infects monocytes and macrophages, forms a characteristic morula (a mulberry-like inclusion body) in the cytoplasm; A. phagocytophilum infects granu-locytes, sometimes also with morula.

How do infections present?

Answer: Most cases are asymptomatic, but more severe cases present like Rocky Mountain spotted fever (RMSF) except that the typical rash does not occur (ie, high fever, headache, and myalgias).

What diseases do Ehrlichia chaffeensis and Anaplasma phagocytophilum cause?

Answer: Ehrlichia chaffeensis: monocytic ehrlichiosis Anaplasma phagocytophilum: granulocytic anaplasmosis

A young man presents with enlarged tender inguinal lymph nodes with draining sinuses and painful genital ulcers. He admits to recent unprotected sex. What is the likely diagnosis and causative organism?

Answer: Lymphogranuloma venereum caused by C. trachomatis (LI, L2, L3)

A 1-month-old infant, whose mother has a history of C. trachomatis genital infections, develops pneumonitis. How would you confirm the diagnosis of chlamydial pneumonitis?

Answer: Exudates from the respiratory tract revealing cytoplasmic inclusions in epithelial cells seen with Giemsa stain or by immunofluorescence, cell culture treated with cycloheximide, and serologic tests