Hasan Exam #2
A sack of potatoes weighing 200 N falls from an airplane. As the velocity of fall increases, air resistance also increases. When air resistance equals 200 N, the sack's acceleration in meters per second per second is
0
An object travels 8 meters in the first second of travel, 8 meters again during the second second of travel, and 8 meters again during the third second. Its acceleration in meters per second per second is
0
What is the acceleration of a car that maintains a constant speed of 100 km/hr for 10 seconds moving eastward?
0
A 10-N falling object encounters 10 N of air resistance. The net force on the object is
0 Newtons
On a balanced see saw, a boy three times as heavy as his partner sits
1/3 the distance from the fulcrum
Ten seconds after starting from rest, an object falling freely downward will have a speed of about
100 m/s
A car has a mass of 1000 kg and accelerates at 1 meters per second per second. What is the magnitude of the net force exerted on the car?
1000 N
A baseball player bats a ball with a force of 1000 N. The ball exerts a reaction force against the bat of
1000 N.
A car accelerates at 2 meters per second per second. Assuming the car starts from rest, how much time does it need to accelerate to a speed of 30 m/s?
15 seconds
If an object falling freely downward were somehow equipped with a speedometer on a planet where the acceleration due to gravity (g) is 20 meters per second per second, then its speed reading would increase each second by
20 m/s
A package falls off a truck that is moving at 30 m/s. In the absence of air resistance, the horizontal speed of the package just before it hits the ground is
30 m/s
Ten seconds after starting from rest, a car is moving at 40 m/s. What is the car's acceleration in meters per second per second?
4.0
A person is attracted toward the center of the Earth by a 500-N gravitational force. The force of attraction of the Earth toward the person is
500 N.
If a car increases its velocity from zero to 60 km/h in 10 seconds, its acceleration is
6 km/h per second
At one instant an object in free fall is moving downward at 50 meters per second. One second later its speed is about
60 m/s
An airplane that flies at 100 km/h with a 10 km/h tailwind travels at 110 km/h relative to the ground. If it instead flies into a 10 km/h headwind, its groundspeed is
90 km/h
The impulse-momentum relationship is a direct result of
Newton's 2nd law
If an object of constant mass experiences a constant net force, it will have a constant
acceleration
When you stand at rest on a pair of bathroom scales, the readings on the scales will always
add to equal your weight
A truly educated person is knowledgeable about
all of these
Science, art, and religion do not contradict one another because
all three have different domains
Suppose you're coasting on level ground in a car at 60 km/h and apply the brakes until you slow to 40 km/h. When you suddenly release the brake, the car tends to
continue moving at 40 km/h in the absence of forces.
A skydiver steps from a helicopter and falls for 5 seconds before reaching her terminal velocity. During this 5-second interval, her acceleration
decreases
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
When an object falls through the air, its velocity increases and its acceleration
decreases
A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. During this time the acceleration of the ball is always
directed downward
When a train makes a curve, the wheel on the outside part of the curve must travel (relative to the inside wheel)
faster
The newton is a unit of
force
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
A car that travels twice as fast as another when braking to a stop will skid
four times as far
A kilogram is a measure of an object's
inertia at rest, mass
Whenever the net force on an object is zero, its acceleration
is zero
An object maintains its state of motion because it has
mass
Which of the following is not a vector quantity?
mass
Compared to a 1-kg block of solid iron, a 2-kg block of solid iron has twice as much
mass, volume, inertia
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.
In science, facts
may change.
A torque acting on an object tends to produce
rotation
Two factors that greatly affect air resistance on falling objects are the
size and speed of the object
Galileo's use of inclined planes allowed him to effectively
slow down the acceleration of free fall
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
Strange as it may seem, it is just as hard to accelerate a car on the moon as it is to accelerate the same car on Earth. This is because
the mass of the car is independent of gravity
A sheet of paper can not be withdrawn from under a container of milk without toppling it if the paper is drawn very slowly. This best demonstrates that
the milk carton has inertia
If less horizontal force is applied to a sliding object than is needed to maintain a constant velocity,
the object eventually slides to a stop
An object of mass 30 kg on Earth. A second object has a mass of 30 Kg on the moon. Which has the greater weight?
the one on Earth
A Mack truck and a Volkswagen traveling at the same speed collide head-on. The impact force is
the same for both
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.
An apple weighs 1 N. The net force on the apple when it is in free fall is
1 N
Exert 2 N force for a distance of 1 m in 2 s and you deliver a power of
1 W
The mass of a pet turtle that weighs 10 N is about
1 kg
The average speed of a horse that gallops a distance of 15 kilometers in a time of 30 minutes is
30 km/h
A rock is thrown vertically into the air. At the top of its path, its acceleration in meters per second per second is
9.8
If you drop an object, it will accelerate downward at a rate of 9.8 meters per second per second. If you instead throw it forcefully downwards, its acceleration (in the absence of air resistance) will be
9.8 meters per second per second
Action and reaction forces comprise the parts of
a single interaction
Disregarding air resistance, objects fall with constant
acceleration
Neglecting friction, a large block of ice and a small block of ice start sliding down an incline together. The heavier block will get to the bottom
at the same time as the light block
A heavy object and a light object are dropped at the same time from rest in a vacuum . The heavier object reaches the ground
at the same time as the lighter object
An object is propelled along a straight-line path by a force. If the net force were doubled, the object's acceleration would
double
A large and a small person wish to parachute at equal terminal velocities. The larger person will have to
get a larger parachute
When a scientist is dishonest and reports false information, he or she
gets no second chance in the scientific community.
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
An object is propelled along a straight-line path in space by a force. If the mass of the object somehow becomes twice as much, its acceleration
halves
An object following a straight-line path at constant speed
has zero acceleration
A skydiver's terminal velocity will be greatest if she falls
head first
Two objects of the same size, but unequal weights are dropped from a tall tower. Taking air resistance into consideration, the object to hit the ground first will be the
heavier object
Science is a body of knowledge that goes back to
humankind's beginnings
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
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
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
The force exerted on the tires of a car to directly accelerate it along a road is exerted by the
road
A rocket becomes progressively easier to accelerate as it travels upward from the ground mainly because
the mass of the rocket decreases as fuel is burned.
The attraction of a person's body toward the Earth is called weight. The reaction to this force is
the person's body pulling on the Earth
While a car travels around a circular track at constant speed its
velocity and acceleration are changing
The two measurements necessary for calculating average speed are
velocity and distance
As an object freely falls downward, its
velocity increases