Hasan Exam #3
Exert 2 N force for a distance of 1 m in 2 s and you deliver a power of
1 W
On a balanced see saw, a boy three times as heavy as his partner sits
1/3 the distance from the fulcrum.
What is the force of gravity on a 500-newton woman standing on the Earth's surface?
500 N
The impulse-momentum relationship is a direct result of
Newton's 2nd law
When you jump from 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 as for a stiff-legged landing. In this way the average force your body experiences is
about 1/10 as great.
The famous Leaning Tower of Pisa doesn't topple over because its center of gravity is
above a place of support
There are no tides to be seen in the community swimming pool because
all parts of it are practically the same distance from the moon.
Strictly speaking, if any electrical device in your car is turned on (such as an air conditioner, headlights, or even a radio) more gasoline is burned by the engine. This statement is
almost always true.
If the Earth had two identical moons in one circular orbit, and the moons were as far apart in that orbit as they could be, the center of gravity of the Earth-moons system would be
at the center of the Earth
When doing somersaults, you'll more easily rotate when your body is
balled up
A car has a head-on collision with another car with the same magnitude of momentum. An identical car driving with the same speed as the first car runs into an enormously massive wall. The greater impulse will occur on the car that is in the collision with the
both impulses will be the same.
An open freight car rolls friction free along a horizontal track in a pouring rain that falls vertically. As water accumulates in the car, the car's speed
decreases
The chef at the infamous Fattening Tower of Pizza tosses a spinning disk of uncooked pizza dough into the air. The disk's diameter increases during the flight, while its rotational speed
decreases
According to Kepler's laws, the paths of planets about the sun are
ellipses
The force that accelerates a rocket in outer space is exerted on the rocket by the
exhaust gases.
During an eclipse of the sun the high ocean tides on Earth are
extra high.
When a train makes a curve, the wheel on the outside part of the curve must travel (relative to the inside wheel)
faster
A car that travels twice as fast as another when braking to a stop will skid
four times as far
According to Newton, the greater the masses of interacting objects, the
greater the gravitational force between them
A clerk can lift containers a vertical distance of 1 meter or can roll them up a 2 meter-long ramp to the same elevation. With the ramp, the applied force required is about
half as much
If you push an object half as far while applying the same force you do
half the amount of work
If you do work on an object in twice the usual time, your power output is
half the usual power output.
When a car is braked to a stop, its kinetic energy is transformed to
heat
An upright broom is easier to balance when the heavier end is
highest, farthest from your hand
If the radius of the Earth somehow decreased with no change in mass, your weight would
increase
Padded dashboards in cars are safer in an accident than nonpadded ones because an occupant hitting the dash has
increased time of impact, decreased impact force.
Consider a rotating donut-shaped space habitat where living quarters are on the inside surface farthest from the axis. If the rotational speed of the habitat increases, the apparent weight of people inside
increases
Two objects move toward each other because of gravity. As the objects get closer and closer, the force between them
increases
When a twirling ice skater brings her arms inward, her rotational speed
increases
The main reason ocean tides exist is that the pull of the moon
is greater on oceans closer to the moon and less on oceans farther from the moon.
Two pool balls, each moving at 2 m/s, roll toward each other and collide. Suppose after bouncing apart, each moves at 4 m/s. This collision violates conservation of
kinetic energy
An object that has potential energy may have this energy because of its
location
When you are in the way of a fast-moving object and can't get out of its way, you will suffer a smaller force of impact if you decrease its momentum over a
long time
Compared to falling on a wooden floor, a wine glass may not break when it falls to a carpeted floor because of the
longer time to stop.
Compared to the force that brings a small car to a stop, the force required to bring a heavy truck traveling at the same speed to a stop
may be less and may be more.
A heavy truck and a small truck roll down a hill. Neglecting friction, at the bottom of the hill, the heavy truck will have greater
momentum
If the speed of a moving object doubles, then what else doubles?
momentum
What does an object have when moving that it never has when at rest?
momentum
Horses that move with the slowest linear speed on a merry-go-round are located
near the center
An industrial flywheel has a greater rotational inertia when most of its mass is
nearest the rim
The best time for digging clams (when the low tide is extra low) is during the time of the
new or full moon
Consider two planets in space that gravitationally attract each other. If the masses of both planets are doubled, and the distance between them is also doubled, then the force of attraction between them is
none of these
The force of gravity acts on all apples on an apple tree. Some apples are twice as far from the ground as others. These twice-as-high apples, for the same mass, have
practically the same weight
Suppose you are at the center of a large freely-rotating horizontal turntable in a carnival funhouse. As you crawl toward the edge, the angular momentum of you and the turntable
remains the same, but the RPMs decrease.
Centrifugal forces are an apparent reality to observers in a reference frame that is
rotating
Since each rolling wheel of a railroad train is tapered, the narrow part of the wheel has a tangential speed that is
smaller than that of the wide part.
To weigh less in the northern hemisphere, you should move to a location
south
A person weighs less at the equator than at the poles. The main reason for this has to do with the
spin of the Earth.
Which has greater kinetic energy, a car traveling at 30 km/hr or a car of half the mass traveling at 60 km/hr?
the 60 km/hr car
Two identical freight cars roll without friction (one at 1 m/s, the other at 2 m/s) toward one another on a level track. They collide, couple together, and roll away in the direction that
the faster car was initially going
Which is most responsible for the ocean tides?
the moon
If the sun collapsed to a black hole, the Earth's gravitational attraction to it would be
the same
The reason a communication satellite does not crash into the Earth is that the
the satellite has a sufficient tangential speed
Which pulls on the oceans of the Earth with the greater force?
the sun
Suppose a gun were made of a strong but very light material. Suppose also that the bullet is more massive than the gun itself. For such a weapon
the target would be safer than the shooter.
In order 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 upon impact. Doing this reduces the force of impact on the player's hand principally because the
time of impact is increased.
Two identical arrows, one with twice the kinetic energy of the other, are fired into a hay bale. The faster arrow will penetrate
twice as far as the slower arrow
When an object is raised above the ground it gains a certain amount of potential energy. If the same object is raised twice as high it gains
twice as much potential energy
Inside the earth, tidal forces for the movement of lava result from
unequal forces acting on different parts of earth.
To turn a stubborn screw, it is best to use a screwdriver that has a
wide handle
An object is placed exactly halfway between the Earth and moon. The object will fall toward the
Earth
The Earth's gravitational field extends
both inside and outside the Earth and throughout the entire universe.
You're driving down the highway and a bug spatters into your windshield. Which undergoes the greater change in momentum?
both the same
When a rifle is fired it recoils so both the bullet and rifle are set in motion. The rifle and bullet ideally acquire equal
but opposite amounts of momentum
A torque acting on an object tends to produce
rotation
A karate expert executes a swift blow and severs a cement block with her bare hand. The magnitude is the same for the
A) force on both the block and the expert's hand. B) impulse on both the block and the expert's hand C) time of impact on both the block and the expert's hand.
A heavy pile driver starting from rest falls on a pile with a force that depends on
A) the distance the pile is moved. B) the original potential energy of the driver. C) the original height of the driver.
A 1-kg ball dropped from a height of 2 m rebounds only 1.5 m after hitting the ground. The amount of energy converted to heat is about
more than 2.0 J.
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