Physics Final Exam

What is the cost of operating a 3-W electric lamp for 2 years if the cost of electricity is $0.08 per KW.h?

$4.2048

A 100-g toy car is propelled by a compressed spring that starts it moving. The car follows the curved track. Show that the final speed of the toy car is __ m/s, if its initial speed is 2 m/s and it coasts up the friction less slope, gaining . 18 m in altitude.

.687 m/s

What is the acceleration of a car that maintains a constant velocity of 55 mi/hr for 10.0 seconds?

0

The amount of net force required to keep a 5-kg object moving rightward with a constant velocity of 2 m/s is ______________

0 N

A ball is thrown 5m straight up. It takes 0.2 s to return back to the start position. What is the ball displacement after that time?

0 m

A swimmer swims 20 laps in a north-‐south facing pool in 7.00 minutes. Her first lap is toward the north. Her displacement and average velocity at the end of the 20 laps are

0,0

What is the amplitude of the wave in the diagram below?

0.03 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/s^2) and air resistance is negligible)

0.072 m

1 km/hr is equal to ______ m/s

0.28 m/s

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/s^2) and air resistance is negligible

0.44 m

A 10-N object moves to the left at 1 m/s. Its kinetic energy is approximately ________?

0.5

A pendulum makes exactly 40 vibrations in 20.0 s. Its period is

0.500 s

How much work is done by the boy pulling his sister 30 m in a wagon with an angle of 48 degrees to the horizontal using a force of 60 N? Assume no friction acts on the wagon.

1.2 kJ

How many waves are shown in the diagram above?

1.5

An object is launched at a velocity of 20 m/s in a direction making an angle of 25° upward with the horizontal. What is the total flight time (between launch and touching the ground) of the object?

1.72 s

A 50 kg platform diver hits the water below with a kinetic energy of 5000 Joules. The height (relative to the water) from which the diver dove was approximately ______ meters.

10

If you push on a wall with a force of -10 Newtons, the force acting on you is

10 N

A ball is projected into the air with 100 J of kinetic energy which is transformed to gravitational potential energy at the top of its trajectory. When it returns to its original level after encountering air resistance, its kinetic energy is ____?

100 J or Less than 100 J

An airplane moves at 141 km/h toward the northeast (45 degrees). What is its component velocity in the northward direction?

100 km/hr

Bronco is a skydiver. His mass is 100 kg. What is his weight in Newtons?

1000 N

An airplane that flies at 100 km/h in a 100 km/h hurricane crosswind has a speed (relative to the ground) of?

141 km/hr

If a 10 kilogram object accelerates suddenly at 15 m/s2, how much force was applied to the object?

150 N

How much force is needed to accelerate a 90 kg skier 2 m/s^2?

180 N

A type of cuckoo clock keeps time by having a mass bouncing on a spring, usually something cute like a cherub in a chair. What force constant (k) is needed to produce a period of 0.500 s for a 0.0150 kg mass?

2.37 N/m

What is the frequency of a wave that has a speed of 0.4 m/s and a wavelength of 0.020 meter?

20 Hz

Which of the following frequency ranges can most humans hear?

20 Hz to 20,000 Hz

A person is pulling west with 35 N of force against a person pulling east with 15 N of force. What is the net force?

20 N west

The average speed of an object which moves 10 kilometers (km) in 30 minutes is _____________

20 km/hr

A ball is kicked with an initial velocity of 16 m/s in the horizontal direction and 12 m/s in the vertical direction. At what speed does the ball hit the ground?

20 m/s

A fireman, stays 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, what is maximum height of the water?

20.4 m

A student adds two vectors with magnitudes of 200 and 40. Which one of the following is the closest possible choice for the magnitude of the resultant?

200

A period of 0.005 seconds would be equivalent to a frequency of

200 Hz

If the frequency of a wave is 24 Hz and the wavelength is 10 m, the wave's speed is

240 m/s

Verify the ranges for the projectiles motion for an initial velocity of 50 m/s at the given initial angles= 45 degree. ( g = 9.8 m/s^2)

255 m

When poked by a spear, an operatic soprano lets out a 1200 Hz shriek. What is its wavelength if the speed of sound is 345 m/s

28.8 cm

A 4000 g object has a momentum of 12 kg*m/s. The objects speed is ____ m/s.

3

If it takes one minute for an airplane to reach speed 100 m/s from start to take -off. How long is the take- off path (airplane displacement in that time).

3 km

How many joules of energy are in one kilowatt-hour?

3.6 MJ

Which two angles will produce the same range? (in degrees)

30 and 60

A baseball pitcher delivers a fast ball. During the throw, the speed of the ball increases from 0 to 30.0 m/s over a time of 0.100 seconds. The average acceleration of the baseball is ______________ m/s^2

300

On takeoff, a rocket accelerates from rest at a rate of 50.0 m/s^2 for exactly 1 minute. The rocket's speed after this minute of steady acceleration will be ______________ m/s

300

When a teacher stands at the front of the class, the force of gravity pulls her toward the ground. The ground pushes back with an equal and opposite force. This is an example of which of Newton's Laws of Motion?

3rd

If the distance from point A to point B in the diagram below is 60 cm, then the wavelength is

40 cm

Find the frequency of a tuning fork that takes 15? to complete one oscillation. (she didn't put a number who tf knows)

400 Hz

Which angle produces the greatest range?

45 degrees

An arrow is drawn back so that 50 Joules of potential energy is stored in the stretched bow and string. When released, the arrow will have a kinetic energy of ____ Joules.

50

A platform diver weighs 500 N. She steps off a diving board that is elevated to a height of 10 meters above the water. The diver will possess _____ Joules of kinetic energy when she hits the water.

5000

A bullet in a gun is accelerated from the firing chamber to the end of the barrel at an average rate of 6.2 x 10^5 m/s^2 for 8.1 x 10^-4 s. What is its muzzle velocity (that is, its final velocity)?

502 m/s

Using 1 kJ of work, a small object is lifted from the ground floor to the third floor of a tall building in 20 sec. What power was required in this task?

50W

A powerful motorcycle can accelerate from rest to 26.8 m/s (100 km/h) in only 3.90 s. How far does it travel in that time?

52.3 m

Two people are pulling a refrigerator into a garage. One person is pulling south with 30 N of force, while the other person is pulling south with 25 N of force. What is the net force?

55 N south

A light inextensible rope is used to pull a particle of mass 2.5 kg along a rough horizontal plane. If the tension in the rope (applaied force) is 25 N and acts at an angle of 25◦ above the horizontal and the coefficient of kinetic friction between the particle and the surface is 0.55, what is the acceleration of the particle?

6 m/s^2

What is the length of a pendulum that has a period of 0.500 s?

6.21 cm

Suppose you take a trip that covers 180 km and takes 3 hours to make. Your average speed is ____ km/hr

60 km/hr

How much work does a supermarket checkout attendant do on a ca of soup he pushes 50 cm horizontally with a force of 15 N?

7.5 J

What frequency is received by a person watching an oncoming ambulance moving at 110 km/h and emitting a steady 800 Hz sound from its siren? the speed of sound on this day is 345 m/s.

878 Hz

A runner in a race takes 2.7 seconds to go from the 40 meter mark to the 70 meter mark. How far would the runner go in 8 seconds if this speed is maintained?

89 m

Gravitational Acceleration "g" on the Earth has the magnitude of

9.8 m/s^2

A car travels north at 30 m/s for one half hour. It then travels south at 40 m/s for 15 minutes. The total distance the car has traveled and its displacement are:

90 km, 18 km N

Which requires more work: lifting a 50 kg crate a vertical distance of 2 m or lifting a 25 kg crate a vertical distance of 4 m?

Both require the same amount of work

The law of _______ of energy states that energy cannot be created or destroyed.

Conservation

A truck driving along a highway road has a large quantity of momentum. If it moves at the same speed but has twice as much mass, its momentum is _____.

Doubled

Waves transfer what from a source to a receiver?

Energy

What is NOT a unit of power?

Joule

Which law states the need to wear seatbelts?

Newton's first law

Which of Newton's Three Laws does the following statement satisfy? An object at rest tends to stay at rest and an object in motion tends to stay in motion in a straight line at a steady speed until an unbalanced force acts upon it.

Newton's first law

Which of Newton's Three Laws does the following statement satisfy? The relationship between an object's mass (m), its acceleration (a), and the applied force F is F=ma. Acceleration and force are vectors. This law requires that the direction of the acceleration vector is in the same direction as the net force vector.

Newton's second law

Which of Newton's three laws does the following example illustrate? If you have a hockey puck sliding along a table, it will eventually come to a stop.

Newton's second law

When a crown of mass 14.7 kg is submerged in water, a scale reads only 13.4 kg. Is the crown made of gold? (Density of the water= 1000 kg/m^3 or 1g/cm^3)

No, because density of that crown is 11.3 g/cm^3

What is it called when a sound wave makes an object vibrate at its natural frequency

Resonance

A 1200 kg car and a 2400 kg car are lifted to the same height at a constant speed in a auto service station. Lifting the more massive car requires _____ work.

Twice as much

An object is raised above the ground gaining a certain amount of potential energy. If the same object is raised twice as high it gains ________?

Twice as much potential energy

Car A has a mass of 1000 kg and a speed of 60 km/h, and car B has a mass of 2000 kg and a speed of 30 km/h. The kinetic energy of car A is ______?

Twice that of car B

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

a parabola

If an object has an acceleration of 0 m/s^2, then one can be sure that the object is not ______________

changing velocity

If an object is moving eastward and slowing down, then the direction of its velocity vector is ______________

eastward

A football is kicked into the air at an angle of 45 degrees with the horizontal. At the very top of the ball's path, its velocity is?

entirely horizontal

A football is kicked into the air at an angle of 45 degrees with the horizontal. At the very top of the ball's path, its acceleration is? (ignore air resistance)

entirely vertical

According to Newton's Third Law, action and reaction are

equal and opposite direction

Which of the following is defined as a push or a pull?

force

The number of cycles of a periodic wave occurring per unit time is defined as a wave's

frequency

A fullback is running down the football field in a straight line. He starts at the 0-yard line at 0 seconds. At 1 second, he is on the 10-yard line; at 2 seconds, he is on the 20-yard line; at 3 seconds, he is on the 30-yard line; and at 4 seconds, he is on the 40-yard line. This is evidence that

he is moving with a constant speed

The tendency of matter to remain in constant motion unless acted on by an outside, unbalanced force is called

inertia

At what point in its path is the horizontal component of the velocity (Vx) of a projectile the smallest?

it is the same throughout the path

If the particles of the medium are vibrating to and from in the same direction of energy transport, then the wave is a

longitudinal wave

What's the SI unit for speed?

m/s

If car A passes car B, then car A must be ______________

moving faster than car B, but not necessarily accelerating

Is a car accelerating if it's moving at a high speed in a straight lane?

no

The speed-time graph for a particle moving at constant speed is a straight-line ______________ to the time axis.

parallel

Which one of the following CANNOT transmit sound?

perfect vacuum (liquid air, gaseous oxygen, liquid water, solid steel all CAN transmit sound)

The main factor which effects the speed of a sound wave is the

properties of the medium

As an object speeds up uniformly , its ______________

speed increases

Name the instrument used to measure instantaneous speed of a vehicle

speedometer

As in the video "A bullet shoot vs bullet drop", the measurable times were

the same

A boat moves through the water in a river at a speed of 8 m/s relative to the water. The boat makes a trip downstream and then makes a return trip upstream to the original starting place. Which trip takes longer?

the upstream trip

When the particles of a medium are vibrating at right angles to the direction of energy transport, then the wave is a

transverse wave

An object's inertia depends on its mass. T/F?

true

vectors must include what two things?

unit and direction

What type of quantity is characterized by both magnitude and direction?

vector

If an object is moving eastward and slowing down, then the direction of its acceleration vector is ______________

westward