Introductory Physics I Lecture 1305 - Final Test (San Antonio College, prof. Albert Aviles)
The mass of a pet turtle that weighs 100 N is about
10kg
The force of friction on a sliding object is 11 N. The applied force needed to maintain a constant velocity is
11 N
A rock suspended by a string weighs 5 N out of water and 3 N when submerged. What is the buoyant force on the rock?
2N
two projectiles are fired from ground level at equal speeds but different angles. one is fired at an angle of 30 degrees and the other at 60 degrees. neglecting air resistance, the projectile to hit the ground first will be the one fired at
30 degrees
What is the buoyant force acting on a 30-ton ship floating in the ocean?
30 tons
Before ice can form on a lake, all the water in the lake must be cooled to
4 C
If a projectile is fired straight up at a speed of 20 m/s, the total time to return to its starting position is about
4 seconds.
A car moves 2 times as fast as another identical car. Compared to the slower car, the faster car has
4 times the KE
You run horizontally at 4 m/s in a vertically falling rain that falls at 4 m/s. Relative to you, the raindrops are falling at an angle of
45 degrees
An object lifted 10 meters gains 200 J of potential energy. If the same object is lifted 40 meters, its potential energy gain is
Four times as much
A skydiver's terminal velocity will be greatest if she falls
Head first
A lunar month is about 28 days. If the moon were closer to the Earth than it is now, the lunar month would be
Less than 28 days
When a load is placed on the middle of a horizontal beam supported at each end, the bottom part of the beam undergoes
Tension
Consider two mercury barometers, one with twice the cross-sectional area of the other. Neglecting capillarity, compared with the wider tube, mercury in the smaller tube will rise
The same height as in the larger tube
The reason that buyoant force acts upward on a submerged object is that
Upward pressure against the bottom is greater that downward pressure against the top of the submerged object.
When a rock thrown straight upwards gets to the exact top of its path, its
Velocity is zero and its acceleration is about 10 meters per second per second.
A completely submerged object always displaces its own
Volume of fluid
An umbrella tends to move upwards on a windy day principally because
air pressure is reduced over the curved top surface
Inside a freely-falling runaway elevator, your
apparent weight is zero
ration of output force to input force of a hydraulic press will be equal to the ratio of the output and input piston
areas
An archer shoots an arrow. Consider the action force to be exerted by the bowstring against the arrow. The reaction to this force is the
arrow's push against the bowstring
Pour a liter of water at 50°C into a liter of water at 30°C and the final temperature of the two becomes
at or about 40 degrees
Our moon travels the fastest as it orbits the Earth when it is
closest
When water at 4 degrees C is heated it expands. When water at 4 degrees C is cooled, it
expands
A player catches a ball. Consider the action force to be the impact of the ball against the player's glove. The reaction to this force is the
force the glove exerts on the ball
Put a pipe over the end of a wrench when trying to turn a stubborn nut on a bolt, to effectively make the wrench handle quadrpe as long, you will multiply the torque by
four
A 1000-kg car and a 4000-kg car are hoisted the same distance. Raising the more massive car requires
four times as much work
An object following a straight-line path at constant speed
has zero acceleration
When a boat sails from fresh water to salt water, the boat will float
higher in the water
If the radius of the Earth somehow decreased with no change in mass, your weight would
increase
When a twirling ice skater brings her arms inward, her rotational speed
increases
When a volume of air is compressed, its temperature
increases
When the distance between two stars decreases by half, the force between them
increases to four times as much
If one object has three times as much mass as another object, it also has three times as much
inertia
A skydiver steps from a helicopter and falls for few second until she reaches her terminal velocity. Thereafter, until she opens her parachute, his acceleration
is Zero
Your feet feel warmer on a rug than on a tile floor because a rug
is better insulator than the tile
For an action force, there must be a reaction force that
is exactly equal in magnitude
Ice cubes submerged at the bottom of a liquid indicate that the liquid
is not displaced by the submerged ice, is less dense than ice.
Whenever the net force on an object is zero, its acceleration
is zero
When a iron ring is heater, the hole becomes
larger
A pair of tennis balls fall through the air from a tall building. One ball is regular and the other is filled with lead pellets. The ball to reach the ground first is the
lead-filled ball
The faster fluid moves, the
less its internal pressure
An object may have potential energy because of its
location.
One of the main reasons one can walk barefoot on red-hot coals of wood without burning the feet has to do with
low thermal conductivity of the coals
An object that has kinetic energy must be
moving
A block of wood weighing 6N in air, is difficult to fully submerge in a pool of mercury because the buoyant force when fully submerged is
much more than 6N
An industrial flywheel has a greater rotational inertia when most of its mass is
nearest the rim
Which is most responsible for the ocean tides?
the moon
What makes an element distinct?
the number of protons
Compared to the energy it takes to separate oxygen and hydrogen from water, the amount of energy given off when they recombine is
the same
About how high can water be theoretically lifted by a vacuum pump at sea level?
10.3 m
When weight is applied to the top of a stone arch, all of the stone blocks in the arch undergo
Compression
A 10-N falling object encounters 10 N of air resistance. The net force on the object is
0N
If a pencil's length and diameter are both multiplied by 100, then its volume is multiplied by
1,000,000
On a balanced seesaw, a boy three times as heavy as his partner sits
1/3 the distance from the fulcrum
If no external forces are acting on a moving object, it will
Continue moving at the same velocity
A ball is moving at 3 m/s and has a momentum of 36 kg m/s. What is the ball's mass?
12kg
If a gram of antimatter meets a kilogram of matter, the amount of mass to survive is
999 grams
If an object of constant mass experiences a constant net forca, it will have a constant
Acceleration
Hang from a pair of gym rings and the upward support forces of the rings will always
Add up to equal your weight
An object is mechanical equilibrium is an object
At rest; Moving with constant velocity; and Having no acceleration
Which has the greater density, a lake full of water or a cup full of lake water?
Both have the same density
An atomic mass unit (amu) is 1/12 the mass of
a carbon atom
A good heat conductor is
a poor insulator
You wish to bolt a sign to a horizontal I-beam supporting a bridge. You will weaken the beam least if you drill the bolt-holes through the
a web effect
Compared to all liquids, solids, and gases in the universe, plasmas are the most
abundant
If the Earth's mass decreased to one-half its original mass with no change in radius, then your weight would
decrease to one half your original weight
Consider a sample of ice at 0 degrees C. If the temperature is decreased, the volume of the ice
decreases
A skydiver jumps from a high-flying plane. As her velocity of fall increases, her acceleration
decreases.
A car travels in a circle with constant speed. The net force on the car is
directed toward the center of the curve
If the mass of an object were to double while its volume remains the same, its density would
double
A freight train rolls along a track with considerable momentum. If it rolls at the same speed but has twice as much mass, its momentum is
doubled
When gas in a container is squeezed to half its volume, and the temperature remains the same. the gas pressure
doubles
When gas in a container is squeezed to half its volume, its density
doubles
The Bernoulli effect causes passing ships to be drawn together when the ships are close and moving in
either the same or opposite directions
The chemical properties of matter comes mostly from its
electrons
The volume of matter comes mostly from its
electrons
The force of gravity does work on a satellite when it is in
elliptical orbit
In an electrically neutral atom, the number of protons in the nucleus is balanced by an equal number of
orbital electrons
Acceleration is greater for a satellite when it is at the
perigee
When a common fluorescent lamp is on, the mercury vapor inside is actually in a
plasma state
The weight of matter comes mostly from its
protons
When a star collapses to form a black hole, its mass
remains the same
When an ice cube in a glass of water melts, the water level
remains the same
A projectile is fired vertically from the surface of the Earth at 5 km/s. The projectile will
rise and fall back to the Earth's surface
The higher the temperature of an object
shorter the wavelengths it radiates.
To multuply the input force of a hydraulic lift, the input end should be the one having the
smaller diameter piston
If you drop a stone into a hole drilled all the way to the other side of the Earth (neglect the molten core), the stone will
speed up until it gets to the center of the Earth.
A ring, a disk, and a solid sphere begin rolling down a hill together. The one to reach the bottom first is the
sphere
Heat energy travels from an object with a high
temperature to an object with a lower temperature
It is correct to say that impulse is equal to
the change in momentum
A hydraulic press multiplies a force by 100. This multiplication is done at the expense of
the distance through which the forces acts
A car traveling at 100 km/hr strikes an unfortunate bug and splatters it. The force of impact is
the same for both
To catch a ball, a baseball player extends the hand forward before impact with the ball and then lets it ride backward in the direction of the ball's motion .. Doing this reduces the force of impact on the player's hand principally because the
time of impact is increased
A flywheel's mass is twice that of another of the same size and shape. The more massive flywheel's rotational inertia is
two times the other's.
The source of every sound is something that is
vibrating
During a very cold winter, water pipes sometimes burst. The reason for this is
water expands when freezing
A dam is thicker at the bottom than at the top partly because
water pressure is greater with increasing depth
A ballon is buoyed up with a force equal to the
weight of air it displaces
Half way to the center of a completely hollow planet with a thin uniform shell, your weight would be
zero