Physics Final Sem 2

Suppose that a car traveling to the east (+x direction) begins to slow as it approaches a traffic light. Which statement concerning its acceleration must be correct?

It's acceleration is in the -x direction

James and John dive from an overhang into the lake below. James simply drops straight down from edge. John takes a running start and jumps straight out from the cliff with an initial horizontal velocity of 25 m/s. Compare the time it takes each to reach the lake below

James and John will reach the surface of the lake at the same time

For a general projectile motion, the vertical component of a projectile's acceleration

Remains a non-zero constant ?

Roll a bowling ball off the edge of a table. As it falls, it's horizontal component of velocity

Remains constant

A rifle recoils while firing a bullet. The speed of the rifles recoil is small because the

Rifle has much more mass than the bullet

A child swings to an fro on a playground swing. If the child stands rather than sits, the time for a to and fro swing is

Shortened

For a system in static equilibrium

The resultant forces and torques must both be zero

A mass oscillates on the end of a spring, both on Earth and on the Moon. Where is the period the greatest?

The same on both the earth and the moon

An elastic collision of two objects is characterized by the following

Total kinetic energy of the system remains constant, total momentum of the system is comserved

A block of ,ass slides down a frictionless plan inclined at an angle theta with the horizontal. The gravitational force is directed

Toward the center of the earth

Consider a solid sphere of radius R and mass M rolling without skipping. Which form of kinetic energy is larger, translational or rotational?

Translational kinetic energy is larger

The frequency of a simple pendulum depends on It's length It's mass The acceleration due to gravity All of these Two of these

Two of these

The Earth moves about the Sun in an elliptical orbit. As the Earth moves close to the Sun, then which of the following best describes the orbiting speed of Earth about the Sun?

Increased

The momentum of an isolated system is conserved

Only in elastic collisions

Communications and weather satellites always appear at the same place in the sky. This is because these satellites are

Orbiting the earth with a 24 hour leriod

A job is done slowly, while an identical job is done quickly. Both jobs require the same amount of work, but different amounts of

Power

Halley's Comet is in a highly elliptical orbit around the sun. Therefore the speed of Halley's Comet while traveling around the sun

Increases as it nears the sun

The phenomenon of beats results from sound

Interference

The total mechanical energy of a system

Is constant if only conservative forces act

For general projectile motion, the horizontal component of a projectile's acceleration

Is zero

A 70-kg person stands at the seashore gazing at the tides. How large is the gravitational force on that person due to the Moon? The mass of the Moon is 7.35x1022kg and the distance to the moon is 3.82x108 m?

0.0024 N

A boy throws a rock with an initial velocity of 2.11 m/s at 30 degrees above the horizontal. How long does it take for the rock to reach the maximum height of its trajectory if air resistance is negligibly small?

0.108 s

A stone is thrown horizontally with an initial speed of 10 m/s from the edge of a cliff. A stopwatch measures the stone's trajectory time from the top of the cliff to the bottom to be 4.3 s. What is the height of the cliff if air resistance is negligibly small?

0.211 s

A 15.0 kg child is sitting on a playground teeter-totter, 150 m from the pivot. What is the minimum distance, on the other side of the pivot such that a 220 N force will make the child lift off the ground?

1.00

A 5 kg shark swimming at a speed of 1 m/s swallows an absent minded 1 kg fish swimming toward it at 4 m/s. The speed of the shark after this meal is

1/6 m/s

A machine puts out 100 Watts of power for ever 1000 Watts put into it. The efficiency of the machine is

10%

An airplane travels at 141 km/h 45 degrees north of east. What is its component of velocity due north?

100 km/h

Find the orbital speed of an ice cube in the rings of Saturn. The mass of Saturn is 5.68x1026 kg, and use an orbital radius 1.00x105kg

19.5km/s

A .140 kg basketball is dropped from rest. It has a speed of 1.20 m/s. The ball is in contact with the ground for .0140. What is the average force extorted by the ground on the ball during the time of contact?

22.0 N

An ideal spring stretches by 21.0 cm when a 135 N object is hung from it. If instead you hang a fish from this spring what is the weight of a fish that would stretch the spring by 41.0 cm?

264 J

How much kinetic energy does a .30 kg stone have if it is thrown at 43 m/s

280 J

A 4 kg ball has a momentum of 12 kg m/s. What is the balls speed?

3 m/s

A 2000 kg car experiences a braking force of 10,000 N and skids to a stop in 6 seconds. The speed of the car just before the brakes were applied was

30 m/s

In an organ pipe, open at both ends, is 5.20 m long. What is its fundamental frequency? The speed of air is 343 m/s

33.0 Hz

A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 km east, and then 1.0 km north to return to its starting point. The trip takes 45 min. What was the bear's average speed

4.00 km/h

Earths radius is 6.38x106 m, and it completes one revolution every day. What is the tangential speed of a person standing on the equator?

464 m/s

Two planets have the same surface gravity, but planet B has twice the radius of planet A. If planet A has mass m what is the mass of planet B?

4m

A traveler pulls on a suitcase strap at an angle 36 degrees above the horizontal. If 682 J of work are done by the strap while moving the suitcase a horizontal distance of 15 m, what is the tension in the strap?

56 N

The beat frequency produced when a 240 hertz tuning fork and a 246 hertz tuning fork are sounded together is

6 hertz

In a supermarket you place a 5 lb (22.3 N) bag of oranges on a scale. The scale starts to oscillate at 2.70 Hz. What is the force constant of the scale?

654 N/m

If I weigh 741 N on Earth and 5320 N on another planet what is the acceleration due to gravity on that planet?

70.4 m/s2

At a given point above Earths surface the gravitational field strength is equal to 7.8 m/s2. What is the altitude of this point above Earths surface? ( M earth = 5.97x1024 kg, R earth = 6.37x106 m)

770 km

An athlete competing in the long jump leaves the ground with a speed of 9.14 m/s at an angle of 55 degrees with the vertical. What is the length of the athlete's jump if air resistance is of no significance?

8.0 m

An old LP record that is originally roasting at 33.3 rad/s is given a uniform angular acceleration of 2.15 rad/s2. Through what angular displacement has the record turned when it's angular speed is 72.0 rad/s?

948 rad

An object is moving with a constant non-zero acceleration in the +x direction. The position versus time graph of the object is

A parabolic graph

Sound waves cannot travel in

A vacuum

A standing wave occurs when A wave reflects upon itself The speed of the wave is zero or nonzero Two waves overlap The amplitude of a wave exceeds its wavelength

A wave reflects upon itself Two waves overlap

When you jump fro, an elevated position you usually bend your knees upon reaching the ground. By doing this, you make the time of the impact about 10 times as great from a stiff-legged landing. In this way the average force your body experiences is

About 1/10 as great

The slope of a velocity versus time graph gives

Acceleration

Which of the following are characteristics of a mass in simple harmonic motion? The motion repeats at regular intervals The motion is sinusoidal The restoring force is proportional to the displacement from equilibrium

All of the above

A moving object has Speed Momentum Velocity Energy All of these

All of these

Which has zero acceleration? An object: In translational equilibrium Moving at constant velocity At rest All of these None of these

All of these

The vibrations of a longitudinal wave in a direction

Along the direction of wave travel

Ina resonating pipe which is open at both ends, there

Are displacement antibodies at each end

The rotational inertia of your leg is greater when your leg is

Bent

Your driving down the highway and a bug spatters into your windshield. Which undergoes the greater change in momentum during the time of contact?

Both the same

A figure skater is spinning slowly with arms outstretched. She brings her arms in close to her body and her angular speed increases dramatically. The speed increase is a demonstration of

Conservation of angular momentum: her moment of inertia is decreased, and so her angular speed must increase to conserve angular momentum

Two wave pulses with equal positive amplitudes pass each other on a string. One is traveling toward the right and the other toward the left. At the point that they occupy the same region of space at the same time

Constructive interference occurs

Your pet hamster sits on a record player whose angular speed is constant. If he moves to a point twice as far from the center then his linear speed

Doubles

A Doppler effect occurs when a source of sound moves

Either towards you or away from you

In a game of pool, the white cue ball hits the #5 ball and stops, while the #5 moves away with the same velocity as the cue ball had originally. The type of collision is

Elastic

Your bat hits the ball pitched to you with a 1500 N instantaneous force. The ball hits the bat with an instantaneous force whose magnitude is

Exactly equal to 1500

If the velocity of an object is zero at some point, then its acceleration must also be zero at that point true or false?

False

A satellite encircles Mars at a distance above it surface equal to 3 times the radius of Mars. If gm is the acceleration due to gravity at the surface of Mars, what is acceleration due to gravity at the location of the satellite?

Gm/16

The planet Jupiter is about 300 times as massive as Earth, yet on its surface you would weigh only about three times as much. This is because

Jupiters radius is 10 times the Earths radius

Minimal orbit speed about Earth is about 8m/s. Minimal orbital speed about the moon would be

Less than 8 km/s

An object may have potential energy because of its

Location

Compressions and rarefactions are characteristic of

Longitudinal waves

When a pendulum clock at sea level is taken to the top of a high mountain, it will

Lose time

A force is a vector quantity because it has both

Magnitude and direction

What quantity is used to measure an objects resistance to changes in rotational motion?

Moment of inertia

An object that has kinetic energy must be

Moving

When a rocket ship accelerating in outer space runs out of fuel, it

No longer accelerates

The maximum acceleration of a car while towing a second car twice its mass, compared to its acceleration with no car in tow, is

One third

Which of the following is not a transverse wave? Light Radio Sounds All of these None of these

Sound

Which of the following is not a vector quantity? Velocity Speed Acceleration

Speed

When you throw a pebble straight up with initial speed V, it reaches a maximum height H with no air resistance. At what speed should you throw it up vertically so it will go twice as high?

Square root of 2

A mass is attached to a spring and oscillates with a period T. If the mass is doubled, what is the new period?

T square root 2

Let the orbital radius of a planet be R and let the orbital period of the planet be T. What quantity is constant for all planets orbiting the sun assuming circular orbits?

T2/R3

Planets would crash into the sun if it wasn't for their

Tangential velocities

The reason an astronaut in an earth satellite feels weightless is that

The astronaut is falling

No work is done on a bowling ball that rolls along a bowling alley because

The force on the ball is at right angles to the balls motion

A Mack truck and a Volkswagen traveling at the same speed have a head-on collision. The vehicle that undergoes the greatest change in velocity will be the

Volkswagen

Double the frequency of a sound and you halve its

Wavelength

Is it possible for a system to have negative potential energy?

Yes, since the choice of the zero of potential energy is arbitrary

The force required to maintain an object at a constant velocity in free space is equal to

Zero